Mailin review: SMTP, Google and Microsoft inbox packs, with warmup and sending bought separately

Mailin (mailin.ai) sells cold email accounts in monthly packs: 200 SMTP accounts for $299, 25 Google accounts for $99, 800 Microsoft accounts for $299 at 5 cold emails a day each. It has an API and exports to Instantly and Smartlead; warmup and sending come from the sequencer you pay for, and payments are not refunded. At 25,000 cold emails a day Mailin with Instantly starts at $2,201 a month before domains; Outreach2day is $716.67 with domains, warmup and the sequencer.

Price 100 mailboxes1,000+ mailboxes? Book a call
  • Warmup and sending included
  • $2.50 a mailbox, 12 minimum
  • Month-to-month billing

Monthly cost · 100,000 cold emails a day, sending included

  1. Mailin + InstantlyMailin + Instantly: from $7,119
  2. Outreach2day mailboxes + InstantlyOutreach2day mailboxes + Instantly: $5,486.67
  3. Outreach2day all-inOutreach2day all-in: $2,866.67
Price per mailbox
from $1.50 in SMTP packs, $1 past 1,000; Microsoft $0.17 at 5 cold emails a day
Outreach2day per mailbox
$2.50 month to month, $1.50 from 100, $0.50 from 1,000
Smallest order
SMTP: 200 accounts for $299 a month; Google: 25 for $99
Mailbox types
Google, Microsoft, SMTP
Warmup
Recommended for 2–3 weeks in its FAQ; no warmup tool or price on the site
MCP server
None found

Every line item from 2,500 to 1,000,000 cold emails a day

Fit

Who Mailin fits

Pick Mailin if

  • You want an email verifier billed by the same vendor
  • You want domain purchase and sequencer export in one REST API
  • You want support in a 24/7 Slack channel

Look elsewhere if

  • You want warmup and a sequencer in the mailbox price
  • You need fewer than 200 SMTP accounts and do not want to pay for a full pack
  • You may need a refund after the first month
  • You want an MCP server for an AI assistant

Overview

What Mailin is

Mailin AI is a cold email infrastructure vendor: it sets up mailboxes on your domains, writes the DNS records (SPF, DKIM, DMARC) and hands the accounts to your sending tool. Three mailbox types sit on separate price tabs: SMTP accounts on Mailin's dedicated servers and IPs, official Google Workspace accounts with admin access, and Microsoft 365 accounts at 100 per domain.

Plans are packs of accounts billed every month. You pick a plan, fill in a 5-minute onboarding form and the accounts arrive in a day (Microsoft in 2 to 3). Domains are bought through Mailin or transferred in at no extra cost; the domain price is not on the site.

Next to the mailboxes Mailin sells an email verifier ($14 per 50,000 checks, catch-all included) and a done-for-you campaign service from $2,499 a month. It has no sequencer of its own: the REST API exports accounts to Instantly, Smartlead, ReachInbox and EmailBison.

Who is behind Mailin? The site names no legal entity or address. The terms of service say "Mailin" and Florida law, the domain was registered in April 2024 behind a privacy service, and LinkedIn lists 2 to 10 employees. Support runs on Slack, 24/7 per the home page.

Cold email mailboxes on SMTP, Google Workspace or Microsoft 365, sold in monthly packs of accounts with automated DNS and export to your sequencer; also an email verifier and a done-for-you service source (opens the vendor's page in a new tab)

The site names no legal entity or address; its terms say "Mailin" and Florida law. LinkedIn lists 2–10 employees. source (opens the vendor's page in a new tab)

Pricing

Mailin pricing

What Mailin charges and what the price includes, next to Outreach2day. Each cell links the page it comes from.

  • Price per mailbox

    Mailin
    SMTP $1.50 ($299 for 200, $749 for 500, $1,499 for 1,000, then $1); Google $2.80–$3.96; Microsoft $0.17–$0.37 at 5 cold emails a day source (opens the vendor's page in a new tab)
    Outreach2day
    $2.50 a month up to 99 mailboxes, $1.50 from 100, $0.50 from 1,000; warmup, sequencer and analytics included at every tier details

  • Smallest order

    Mailin
    SMTP: 200 accounts for $299 a month; Google: 25 for $99 source (opens the vendor's page in a new tab)
    Outreach2day
    12 mailboxes, $30 a month details

  • Domain cost

    Mailin
    Bought through Mailin or your own transferred in; price not published source (opens the vendor's page in a new tab)
    Outreach2day
    $13 a year for a .com, $5 for a .info, registered to you; or connect your own for free details

  • Setup fees

    Mailin
    None listed source (opens the vendor's page in a new tab)
    Outreach2day
    No setup or platform fee; a card fee of 2.9% + $0.30 at checkout on new domains and the first month details

  • Warmup

    Mailin
    Recommended for 2–3 weeks in its FAQ; no warmup tool or price on the site source (opens the vendor's page in a new tab)
    Outreach2day
    IncludedIncluded for the life of the mailbox, 75+ warmup emails a day details

  • Sequencer

    Mailin
    No sequencer; API export to Instantly, Smartlead, ReachInbox and EmailBison, with fields for PlusVibe and MasterInbox source (opens the vendor's page in a new tab)
    Outreach2day
    IncludedIts own sequencer; syncs to Instantly and Smartlead, CSV export for 14 tools details

  • Export to other tools

    Mailin
    IncludedAPI export to Instantly, Smartlead, ReachInbox and EmailBison source (opens the vendor's page in a new tab)
    Outreach2day
    IncludedSyncs to Instantly and Smartlead by API key; CSV export in the import format of 14 tools, EmailBison among them; SMTP/IMAP logins for any other tool details

  • API and MCP

    Mailin
    Partly, or at extra costPublic REST API with a bearer token: domains, mailboxes, servers, exports, verifier. MCP: None found source (opens the vendor's page in a new tab)
    Outreach2day
    IncludedREST API on every account. MCP: Hosted MCP server: domains, mailboxes, warmup, campaigns, replies details

List prices from Mailin's pricing page and Outreach2day's pricing page, checked . Taxes and card fees excluded.

Add-ons and extra costs

SMTP is the default tab: Solopreneur $299 a month for 200 accounts, Business $749 for 500, Enterprise $1,499 for 1,000 with extra accounts at $1 each. Each card says "$1.50 per inbox". The meta description and Mailin's own comparison pages say $1.20 per mailbox; no plan on the pricing tabs shows that price.

Google costs more per account: $99 for 25 ($3.96), $299 for 100 ($2.99), $1,399 for 500 ($2.80). Microsoft costs less per account and sends less: $299 for 800, $749 for 2,500, $1,999 for 12,000, each mailbox limited to 10 emails a day, 5 of them cold and 5 warmup.

Because plans are packs, you pay for the whole pack: 120 SMTP accounts bill as one 200-account pack ($299), and 210 as two ($598). Every plan and what it costs at three volumes is in Mailin pricing.

Full cost

What 2,500, 25,000 and 100,000 cold emails a day cost with Mailin

The same emails a day on every row: Mailin mailboxes at 25 a day (not published for SMTP, so the same 25 as ours; its Microsoft plans allow 5 cold a day) with the Instantly plan it needs to send and warm up, next to Outreach2day mailboxes (25 a day each) in Instantly and Outreach2day on its own.

2,500 a day · 55,000 a month100 Mailin mailboxes at 25 a day, 100 of ours at 25 · USD a month
  1. Mailin + InstantlyMailin + Instantly: from $396
  2. Outreach2day mailboxes + InstantlyOutreach2day mailboxes + Instantly: $268.67
  3. Outreach2day all-inOutreach2day all-in: $171.67
25,000 a day · 550,000 a month1,000 Mailin mailboxes at 25 a day, 1,000 of ours at 25 · USD a month
  1. Mailin + InstantlyMailin + Instantly: from $2,201
  2. Outreach2day mailboxes + InstantlyOutreach2day mailboxes + Instantly: $1,422.67
  3. Outreach2day all-inOutreach2day all-in: $716.67
100,000 a day · 2,200,000 a month4,000 Mailin mailboxes at 25 a day, 4,000 of ours at 25 · USD a month
  1. Mailin + InstantlyMailin + Instantly: from $7,119
  2. Outreach2day mailboxes + InstantlyOutreach2day mailboxes + Instantly: $5,486.67
  3. Outreach2day all-inOutreach2day all-in: $2,866.67
  • Mailin + Instantly

    SMTP mailboxes from $1.50 in SMTP packs, $1 past 1,000; Microsoft $0.17 at 5 cold emails a day · 25 cold emails a day each; Instantly for sending and warmup

    2,500 a day · 55,000 a month

    from $396a month

    at least $224.33 more than Outreach2day all-in

    from $7.20 per 1,000 emails · 100 mailboxesMailboxes alone: $299 a month

    25,000 a day · 550,000 a month

    from $2,201a month

    at least $1,484.33 more than Outreach2day all-in

    from $4 per 1,000 emails · 1,000 mailboxesMailboxes alone: $1,495 a month

    100,000 a day · 2,200,000 a month

    from $7,119a month

    at least $4,252.33 more than Outreach2day all-in

    from $3.24 per 1,000 emails · 4,000 mailboxesMailboxes alone: $4,499 a month

  • Outreach2day mailboxes + Instantly

    Keep Instantly, buy the mailboxes from us; 25 a day each

    2,500 a day · 55,000 a month

    $268.67a month

    $97 more than Outreach2day all-in

    $4.88 per 1,000 emails · 100 mailboxesMailboxes alone: $150 a month

    25,000 a day · 550,000 a month

    $1,422.67a month

    $706 more than Outreach2day all-in

    $2.59 per 1,000 emails · 1,000 mailboxesMailboxes alone: $500 a month

    100,000 a day · 2,200,000 a month

    $5,486.67a month

    $2,620 more than Outreach2day all-in

    $2.49 per 1,000 emails · 4,000 mailboxesMailboxes alone: $2,000 a month

    • 4,000 Outreach2day mailboxes at $0.50 (volume price from 1,000): $2,000
    • 800 domains at $13 a year: $866.67
    • Instantly Hypergrowth + 29 Outbound add-ons (sequencer, warmup): $2,620 source (opens the vendor's page in a new tab)
  • Outreach2day all-in

    Mailboxes, warmup and our sequencer in one bill; 25 a day each

    2,500 a day · 55,000 a month

    $171.67a month

    $3.12 per 1,000 emails · 100 mailboxesMailboxes alone: $150 a month

    • 100 mailboxes at $1.50 (volume price from 100), warmup and sequencer included: $150
    • 20 domains at $13 a year: $21.67
    25,000 a day · 550,000 a month

    $716.67a month

    $1.30 per 1,000 emails · 1,000 mailboxesMailboxes alone: $500 a month

    • 1,000 mailboxes at $0.50 (volume price from 1,000), warmup and sequencer included: $500
    • 200 domains at $13 a year: $216.67
    100,000 a day · 2,200,000 a month

    $2,866.67a month

    $1.30 per 1,000 emails · 4,000 mailboxesMailboxes alone: $2,000 a month

    • 4,000 mailboxes at $0.50 (volume price from 1,000), warmup and sequencer included: $2,000
    • 800 domains at $13 a year: $866.67

Compared at the same emails a day, each vendor at its own published emails per mailbox a day: a cheap mailbox that sends 5 a day costs more per email than one that sends 25. Mailboxes = emails a day ÷ emails per mailbox a day (Mailin: 25, not published for SMTP, so the same 25 as ours; its Microsoft plans allow 5 cold a day; Outreach2day: 25). A month is 22 sending days, so emails a month = emails a day × 22. Monthly list prices on monthly billing; the Instantly plan is the cheapest one that covers the volume. Mailin does not publish a domain price, so its domains (5 mailboxes each) are left out of the total, marked "from"; Outreach2day .com domains at $13 a year, 5 mailboxes per domain. Domains spread over 12 months. Outreach2day mailboxes on comparison pages: $2.50 a mailbox up to 99, $1.50 from 100, $0.50 from 1,000; larger volumes on the Enterprise plan. A mailbox-only vendor cannot send campaigns on its own, so its total is the full sending setup: its mailboxes, domains and the sequencer plan that covers the volume. Instantly is the reference sequencer, on its published plans for the emails and new contacts a month (emails ÷ 3); Smartlead where Instantly publishes no plan; Mailforge with Salesforge, because its mailboxes cannot be warmed in Instantly. The mailbox line is listed on its own in every cell.

Your saving · 100,000 a day

You save $4,252.33 a month ($51,028 a year)with Outreach2day at 100,000 cold emails a day, against Mailin + Instantly at list prices

We move your mailboxes and campaigns for you, free

New · Outreach2day volume pricing

The mailbox price falls from 100 and again from 1,000 mailboxes

Warmup, the sequencer and the replies inbox included at every tier

  1. Up to 99 mailboxes$2.50a mailbox a month
  2. From 100 mailboxes$1.50a mailbox a month
  3. From 1,000 mailboxes$0.50a mailbox a month

Enterprise plan. Better prices for larger volumes.

Book a call

Mailin's SMTP packs are counted at 25 cold emails a mailbox a day, because it publishes no SMTP limit. 2,500 a day take 100 accounts, which bill as the $299 Solopreneur pack; Instantly Hypergrowth adds $97 for sending and warmup: from $396 a month before domains. 100 Outreach2day mailboxes cost $171.67 with domains, warmup and the sequencer.

25,000 a day take 1,000 accounts: from $2,201 with Instantly ($1,495 for five Solopreneur packs + $706) before domains, against $716.67 for 1,000 Outreach2day mailboxes at $0.50. 100,000 a day take 4,000: Enterprise plus 3,000 accounts at $1 is $4,499, from $7,119 with Instantly ($2,620); 4,000 Outreach2day mailboxes are $2,866.67 all in.

On Microsoft at 5 cold emails a day the same volumes take 500, 5,000 and 20,000 mailboxes: $299, $1,498 and $3,998 a month for the packs, plus Instantly and domains.

What Mailin does well

  • SMTP, Google and Microsoft accounts from one vendor
  • A REST API with sequencer exports and domain purchase
  • Accounts delivered in a day, DNS set automatically
  • 24/7 Slack support
  • A low per-account price on Microsoft packs

Verdict

Mailin is a capable mailbox vendor for teams that already run a sequencer: three mailbox types, a real API, fast delivery and Slack support. The bill still needs a sequencer for sending and warmup, the packs round you up to 200, 500 or 1,000 accounts, and nothing is refunded after activation.

Outreach2day puts mailboxes, warmup that keeps running and our own sequencer in one monthly bill: $2.50 a mailbox, $1.50 from 100 and $0.50 from 1,000, with the Enterprise plan on a call for larger volumes. Our mailboxes run on our own infrastructure and land in the inbox; most people think only Google gets there and overpay for it.

At scale

From 25,000 to 1,000,000 cold emails a day

The same setups at larger daily volumes. A vendor without a published price at a size reads “Custom pricing (not published)” and has no bar.

Running 25,000+ a day? Enterprise plan: better prices for larger volumes.Book a call

25,000 a day · 550,000 a month1,000 mailboxes · USD a month
  1. Mailin + InstantlyMailin + Instantly: from $2,201
  2. Outreach2day mailboxes + InstantlyOutreach2day mailboxes + Instantly: $1,422.67
  3. Outreach2day all-inOutreach2day all-in: $716.67
50,000 a day · 1,100,000 a month2,000 mailboxes · USD a month
  1. Mailin + InstantlyMailin + Instantly: from $3,814
  2. Outreach2day mailboxes + InstantlyOutreach2day mailboxes + Instantly: $2,748.33
  3. Outreach2day all-inOutreach2day all-in: $1,433.33
100,000 a day · 2,200,000 a month4,000 mailboxes · USD a month
  1. Mailin + InstantlyMailin + Instantly: from $7,119
  2. Outreach2day mailboxes + InstantlyOutreach2day mailboxes + Instantly: $5,486.67
  3. Outreach2day all-inOutreach2day all-in: $2,866.67
250,000 a day · 5,500,000 a month10,000 mailboxes · USD a month
  1. Outreach2day all-inOutreach2day all-in: $7,166.67
Mailin + Instantly, Outreach2day mailboxes + Instantly: no published price at this volume, so no bar.
500,000 a day · 11,000,000 a month20,000 mailboxes · USD a month
  1. Outreach2day all-inOutreach2day all-in: $14,333.33
Mailin + Instantly, Outreach2day mailboxes + Instantly: no published price at this volume, so no bar.
1,000,000 a day · 22,000,000 a month40,000 mailboxes · USD a month
  1. Outreach2day all-inOutreach2day all-in: $28,666.67
Mailin + Instantly, Outreach2day mailboxes + Instantly: no published price at this volume, so no bar.
Monthly cost of Mailin and Outreach2day setups from 25,000 to 1,000,000 cold emails a day
Setup25,000 a day550,000 a month1,000 mailboxes50,000 a day1,100,000 a month2,000 mailboxes100,000 a day2,200,000 a month4,000 mailboxes250,000 a day5,500,000 a month10,000 mailboxes500,000 a day11,000,000 a month20,000 mailboxes1,000,000 a day22,000,000 a month40,000 mailboxes
Mailin + Instantlyfrom $2,201$1,484.33 morefrom $3,814$2,380.67 morefrom $7,119$4,252.33 moreCustom pricing (not published)Custom pricing (not published)Custom pricing (not published)
Outreach2day mailboxes + Instantly$1,422.67$706 more$2,748.33$1,315 more$5,486.67$2,620 moreCustom pricing (not published)Custom pricing (not published)Custom pricing (not published)
Outreach2day all-in$716.67$1,433.33$2,866.67$7,166.67$14,333.33$28,666.67

Mailboxes = emails a day ÷ emails per mailbox a day (Mailin: 25; Outreach2day: 25). A month is 22 sending days, so emails a month = emails a day × 22. The Instantly plan is the published plan that covers the volume (its contacts and emails); where a vendor publishes no price at that size, the cell says so and the chart leaves it out. Domains at each vendor's published price spread over 12 months; Outreach2day .com domains at $13 a year, 5 mailboxes per domain, are in every total.

Every line at scale

  • Mailin + Instantly, 25,000 a day: 1,000 SMTP accounts: 5 × Solopreneur ($299 for 200) ($1,495) source (opens the vendor's page in a new tab) + 200 domains, price not published (not published) + Instantly Hypergrowth + 7 Outbound add-ons (sequencer, warmup) ($706) = from $2,201
  • Mailin + Instantly, 50,000 a day: Enterprise ($1,499 for 1,000) + 1,000 accounts at $1 ($2,499) source (opens the vendor's page in a new tab) + 400 domains, price not published (not published) + Instantly Hypergrowth + 14 Outbound add-ons (sequencer, warmup) ($1,315) = from $3,814
  • Mailin + Instantly, 100,000 a day: Enterprise ($1,499 for 1,000) + 3,000 accounts at $1 ($4,499) source (opens the vendor's page in a new tab) + 800 domains, price not published (not published) + Instantly Hypergrowth + 29 Outbound add-ons (sequencer, warmup) ($2,620) = from $7,119
  • Outreach2day mailboxes + Instantly, 25,000 a day: 1,000 Outreach2day mailboxes at $0.50 (volume price from 1,000) ($500) + 200 domains at $13 a year ($216.67) + Instantly Hypergrowth + 7 Outbound add-ons (sequencer, warmup) ($706) = $1,422.67
  • Outreach2day mailboxes + Instantly, 50,000 a day: 2,000 Outreach2day mailboxes at $0.50 (volume price from 1,000) ($1,000) + 400 domains at $13 a year ($433.33) + Instantly Hypergrowth + 14 Outbound add-ons (sequencer, warmup) ($1,315) = $2,748.33
  • Outreach2day mailboxes + Instantly, 100,000 a day: 4,000 Outreach2day mailboxes at $0.50 (volume price from 1,000) ($2,000) + 800 domains at $13 a year ($866.67) + Instantly Hypergrowth + 29 Outbound add-ons (sequencer, warmup) ($2,620) = $5,486.67
  • Outreach2day all-in, 25,000 a day: 1,000 mailboxes at $0.50 (volume price from 1,000), warmup and sequencer included ($500) + 200 domains at $13 a year ($216.67) = $716.67
  • Outreach2day all-in, 50,000 a day: 2,000 mailboxes at $0.50 (volume price from 1,000), warmup and sequencer included ($1,000) + 400 domains at $13 a year ($433.33) = $1,433.33
  • Outreach2day all-in, 100,000 a day: 4,000 mailboxes at $0.50 (volume price from 1,000), warmup and sequencer included ($2,000) + 800 domains at $13 a year ($866.67) = $2,866.67
  • Outreach2day all-in, 250,000 a day: 10,000 mailboxes at $0.50 (volume price from 1,000), warmup and sequencer included ($5,000) + 2,000 domains at $13 a year ($2,166.67) = $7,166.67
  • Outreach2day all-in, 500,000 a day: 20,000 mailboxes at $0.50 (volume price from 1,000), warmup and sequencer included ($10,000) + 4,000 domains at $13 a year ($4,333.33) = $14,333.33
  • Outreach2day all-in, 1,000,000 a day: 40,000 mailboxes at $0.50 (volume price from 1,000), warmup and sequencer included ($20,000) + 8,000 domains at $13 a year ($8,666.67) = $28,666.67

Why each plan at scale

Your size

What 2,500 cold emails a day cost a month

121,000+
  • Mailin + InstantlyMailin + Instantlyfrom $396

    100 mailboxes × 25 a day = 2,500 cold emails a day

  • Outreach2day mailboxes + InstantlyOutreach2day mailboxes + Instantly$268.67

    100 mailboxes × 25 a day = 2,500 cold emails a day

  • Outreach2day all-inOutreach2day all-in$171.67

    100 mailboxes × 25 a day = 2,500 cold emails a day

You save $224.33 a month ($2,692 a year)with Outreach2day at 2,500 cold emails a day, against Mailin + Instantly at list prices

We move your mailboxes and campaigns for you, free

Create 100 mailboxes

Switching

Moving from Mailin to Outreach2day

  1. Keep your sequencer

    Connect Instantly or Smartlead in Outreach2day with an API key and the warm mailboxes are added to your account; other tools take a CSV in their import format, or SMTP/IMAP logins. How the export works

  2. Or move the campaigns

    Our sequencer runs campaigns with steps, a send schedule, stop on reply and one inbox for replies; import the contacts as a CSV and recreate the steps. The mailbox price stays $2.50.

  3. Warmup and the overlap

    New mailboxes warm for 14 days before cold email, and warmup keeps running after that. Keep the Mailin mailboxes sending during those two weeks, then shift the volume and cancel Mailin for the end of its billing period.

Mailin plans renew automatically and payments are final, so cancel before the next billing date once the new mailboxes are warm. Domains transferred into Mailin can be pointed at the new provider.

Terms

Mailin limits, setup and terms

Each line links to the vendor's page it comes from.

Smallest order

source (opens the vendor's page in a new tab)
SMTP: 200 accounts for $299 a month; Google: 25 for $99

Setup time

source (opens the vendor's page in a new tab)
5-minute onboarding form, then 1-day delivery (Microsoft 2–3 days); DNS, SPF, DKIM and DMARC set automatically

Mailbox types

source (opens the vendor's page in a new tab)
SMTP on dedicated servers and IPs, Google Workspace and Microsoft 365, on separate price tabs

Domains

source (opens the vendor's page in a new tab)
Bought through Mailin or transferred in at no extra cost; 2–5 inboxes per domain on SMTP and Google, 100 on Microsoft

Sending limits

source (opens the vendor's page in a new tab)
Microsoft: up to 10 emails a mailbox a day, 5 cold and 5 warmup; not published for SMTP or Google

Warmup

source (opens the vendor's page in a new tab)
Recommended for 2–3 weeks in its FAQ; no warmup tool or price on the site

Sequencers

source (opens the vendor's page in a new tab)
No sequencer; API export to Instantly, Smartlead, ReachInbox and EmailBison, with fields for PlusVibe and MasterInbox

API

source (opens the vendor's page in a new tab)
Included Public REST API with a bearer token: domains, mailboxes, servers, exports, verifier

MCP server

source (opens the vendor's page in a new tab)
Not included None found

Support

source (opens the vendor's page in a new tab)
24/7 Slack access to a team of 8 to 10 (technical, deliverability, GTM)

Refunds

source (opens the vendor's page in a new tab)
All payments final and non-refundable; one exception, a 21-day deliverability guarantee with five conditions

Trial

source (opens the vendor's page in a new tab)
No free trial on the site

Features

Other Mailin features

Deliverability guarantee
A refund is considered only after a full 21-day warmup with no cold sends, an escalation within 21 days, sequencer access for Mailin and its recommendations followed source (opens the vendor's page in a new tab)
Email verifier
Standard and catch-all verification, $14 per 50,000 source (opens the vendor's page in a new tab)
Domain transfer
Existing domains transferred in at no extra cost; the API also imports domains from InboxKit source (opens the vendor's page in a new tab)
Done for you
Managed campaigns from $2,499 a month for 100,000 emails source (opens the vendor's page in a new tab)
Prohibited industries
Crypto, political activities and any industry not compliant with anti-spam law source (opens the vendor's page in a new tab)
Scale (vendor's claim)
1,000+ paying clients; "over 500 million emails every month" and, further down the same page, "1.3 billion emails every month" source (opens the vendor's page in a new tab)
Team
LinkedIn: 2–10 employees source (opens the vendor's page in a new tab)

In detail

Refunds and the deliverability guarantee

Mailin's terms make every payment final: subscriptions, setup, warmup, server and domain costs are not refunded, including when results disappoint or you cancel early. The one exception is a 21-day deliverability guarantee, and it has five conditions: you raise the concern within 21 days, run a full 21-day warmup with no cold or marketing sends, give Mailin access to your sequencer and logs, follow its recommendations, and Mailin confirms results below reasonable expectations.

In practice the guarantee covers the warmup phase only. Plan a first month you can afford to lose, because the pack renews automatically until you cancel in the account page or through support.

Sending limits: what the packs really send

Only the Microsoft tab publishes a limit: up to 10 emails a mailbox a day, 5 cold and 5 warmup. 800 Microsoft accounts therefore send about 4,000 cold emails a day, the same as 160 mailboxes at 25 a day.

Mailin publishes no per-mailbox limit for SMTP or Google, so the cost table counts them at 25 a day, the same as ours. At that rate the 200-account Solopreneur pack covers 5,000 cold emails a day once warmed.

API and integrations

The public REST API (bearer token from a login call) covers domains (buy, transfer, check availability), mailboxes, servers, Azure orders, the verifier, and exports to a sequencer with a status call. That is a real advantage for agencies that provision from scripts.

There is no MCP server, so an AI assistant cannot order or manage Mailin accounts on its own. Outreach2day has a hosted MCP server for domains, mailboxes, warmup and campaigns.

Ratings

Mailin ratings

We found no Trustpilot or Product Hunt page for Mailin on 2026-10-22, and G2 did not load for us. The site says "Trusted by 1000+ clients".

Or us

Mailin or Outreach2day

We sell cold email mailboxes too. Where our product fits this buyer and where it does not.

Mailin

Stay with Mailin if

  • You need fewer than 12 mailboxes: our minimum order is 12

Outreach2day

Outreach2day fits if

  • You run 100+ mailboxes: $1.50 a mailbox from 100 and $0.50 from 1,000, warmup and the sequencer included; larger volumes on the Enterprise plan
  • You want mailboxes, warmup and sending in one bill, on mailboxes that run on our own infrastructure and land in the inbox
  • You want to pay for the mailboxes you use, from 12, month to month
  • You want an AI assistant to run setup through our MCP server
Price 100 mailboxes1,000+ mailboxes? Book a call

Outreach2day mailboxes send from its own campaigns or from your sequencer; the fields and settings per tool are in the integration docs.

FAQ

Mailin review: questions

What is Mailin AI?

Mailin (mailin.ai) is a cold email infrastructure vendor. It sells SMTP, Google Workspace and Microsoft 365 accounts in monthly packs, sets up the DNS records, exports the accounts to sequencers such as Instantly and Smartlead, and also sells an email verifier and a done-for-you campaign service.

Which company is behind Mailin?

The site does not name a legal entity or an address. Its terms of service refer to "Mailin" and Florida law; LinkedIn lists 2 to 10 employees, and the mailin.ai domain was registered in April 2024 behind a privacy service.

How much does Mailin cost?

SMTP: $299 a month for 200 accounts, $749 for 500, $1,499 for 1,000 and $1 for each account past 1,000. Google: $99 for 25, $299 for 100, $1,399 for 500. Microsoft: $299 for 800, $749 for 2,500, $1,999 for 12,000. All monthly; SMTP shows a yearly option that saves 20%.

What do 25,000 cold emails a day cost with Mailin?

1,000 SMTP accounts at 25 a day: five $299 Solopreneur packs ($1,495), plus Instantly at $706 to send and warm them: from $2,201 a month before domains. 1,000 Outreach2day mailboxes send the same for $716.67 with domains, warmup and the sequencer.

What do 2,500 cold emails a day cost with Mailin?

100 SMTP accounts at 25 a day, billed as the $299 Solopreneur pack, plus Instantly Hypergrowth at $97 to send and warm them: from $396 a month before domains. 100 Outreach2day mailboxes send the same for $171.67 with domains, warmup and the sequencer.

Does Mailin include warmup?

Its FAQ recommends 2 to 3 weeks of warmup, and the site offers no warmup tool or price, so warmup runs in your sequencer. Outreach2day includes warmup for the life of every mailbox.

Does Mailin give refunds?

No, apart from a 21-day deliverability guarantee: you must report the problem within 21 days, finish a 21-day warmup with no cold sends, give Mailin access to your sequencer and follow its recommendations.

Are there Mailin reviews on Trustpilot or G2?

We found no Trustpilot or Product Hunt page for Mailin on October 22, 2026, and G2 did not load for us. The site shows video testimonials and says it is trusted by 1,000+ clients.

Related

More on Mailin

Deliverability call

Talk to our deliverability team

Book a call with the people who run our mailbox infrastructure. We look at your current setup and tell you what to change. Mailboxes are $1.50 from 100 and $0.50 from 1,000; for larger volumes we size an Enterprise plan with you.

  • Review your domains, DNS records and current inbox placement
  • Size the setup: domains, mailboxes per domain and daily volume per mailbox
  • Plan warmup and the move from your current provider or sequencer
  • Larger volumes: the Enterprise plan and its price for your setup

Free call

See open times in your time zone and book on this page.

Or open the booking page

Sources

Each vendor's own pages. Vendors change prices and plans; if something here is out of date, write to support@outreach2day.com and we will fix it.

Mailin
Outreach2day

Full volume from day 14: 25 cold emails a mailbox a day

Add domains, create mailboxes and turn on warmup. You see every mailbox's warmup numbers from day one.

Book a call
Price 100 mailboxes