MailDeck review: Outlook tenants of 100 inboxes, Google and SMTP, built and loaded into your sequencer

MailDeck publishes two different answers to "how many cold emails per inbox a day". The pricing page and FAQ say 4 to 5 for Outlook Normal, 8 to 10 for Premium, 18 to 22 for Google and 11 to 14 for SMTP. The help docs say 10, 12, about 20 and 8.

The gap matters for sizing. At the pricing-page numbers, 1,500 cold emails a day takes 150 to 188 Premium inboxes; at the docs numbers, 125. SMTP moves the other way: the docs number is lower. Size on the lower figure for each type until your own placement data says otherwise.

The home page lists "Warm-up included". The help docs describe how it works: MailDeck's team switches warm-up on in your sequencer, and "your sequencer (Instantly, Plusvibe and the like) runs the warmup emails day to day". Warm-up therefore runs on a sequencer plan you pay for separately. Its own warm-up guide recommends only the Smartlead Premium, Instantly or Pipl.ai pools.

Plan the wait too: 3 to 7 days on Outlook, 15 days on Google and 3 to 4 weeks on SMTP before the first cold email, on top of the 48 to 72 hours of setup. Pre-warmed Outlook tenants at $40 skip it, when the team has them in stock; pre-warmed Google and SMTP were sold out when we checked.

MailDeck's docs use this exact example. On Outlook Premium it is 2 tenants, $80 a month at today's sale price ($110 at the regular price), plus 2 domains from your registrar. Add the sequencer: at about 33,000 emails a month that is Instantly Hypergrowth at $97 a month (Instantly pricing). Total about $177 a month.

On Google alone it is 75 inboxes: $245.25 a month on the Growth plan with 45 extra inboxes, 15 domains, plus the same sequencer. On Outreach2day it is 60 mailboxes at 25 a day, $150 a month with warm-up and the sequencer in that price, plus 12 domains.

Quick Start asks for your registrar's username and password and asks you to switch off two-factor login at the registrar while the team sets up DNS. It also asks for the email and password you use to sign in to your sequencer, so the team can add the inboxes. Both can be saved for the next order.

That is how MailDeck delivers a done-for-you setup in 48 to 72 hours, and many agencies accept it. If your security policy forbids sharing registrar or sequencer passwords, this setup does not work for you as described. Domains registered at Cloudflare are also out, because MailDeck needs to change the nameservers.

The refund policy covers "trial users with a single tenant" within 30 days, and only if the mailboxes were not delivered in working order within 10 to 14 business days. One refund per customer. Content-filter problems are excluded.

The FAQ says you can cancel any time in account settings; the cancellation policy asks for 7 days' notice and keeps charges from the notice period, and the help docs say cancellations go through a person on the team. The terms are governed by Hungarian law, and the footer names The Scaling Group LLC.

The About page says MailDeck manages 4,350,000+ inboxes and 1,200+ domains. With at most 100 inboxes on a domain, 1,200 domains hold at most 120,000 inboxes, so the two numbers cannot both describe the same fleet. InboxKit's MailDeck review from May 2026 quotes the site at 833,900+ inboxes. Treat the scale figures as marketing.

The home page shows a 4.8 Trustpilot score. Trustpilot showed 4.3 from 29 reviews when we checked, with 10% one-star reviews, and the notice "This company has been displaying Trustpilot content incorrectly."