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Short answer
Connect Smartlead with its API key in Outreach2day (Export to sequencer) and export the mailboxes in one click; they are added as SMTP accounts with Smartlead's warm-up off, and new ones follow automatically. Or download the Smartlead CSV and upload it in Email Accounts. Set the daily cap to 25 cold emails per mailbox; warm-up keeps running in Outreach2day.
What you get
- Outreach2day mailboxes added to Smartlead with its API key, one click for all of them or a selection
- Auto export: new mailboxes go to Smartlead as soon as they are created
- Auto reconnect: mailboxes that disconnect in Smartlead are reconnected
- A CSV in Smartlead's import format as the manual route
- Warm-up keeps running in Outreach2day after the export, included in the price
- SPF, DKIM and DMARC already set on every domain
Connect Smartlead and export
In Outreach2day
- Open Export to sequencer. In the app sidebar, open Export to sequencer and click Connect sequencer
- Pick Smartlead and paste its API key. Fill in the connection name, your Smartlead login email and password and the API key, then click Check key. Export, auto export and reconnect need the key
- Choose the settings. Auto export (new mailboxes as soon as they are created), Auto reconnect, and the mailbox scope (all mailboxes or one tag)
- Export. Export all eligible mailboxes or a selection. Mailboxes still being set up, deactivated or frozen are skipped, and mailboxes already exported to this connection are not sent twice
The same works from an AI assistant: with the Outreach2day MCP server, list_sequencers shows the connection and export_mailboxes_to_sequencer exports the mailboxes after you confirm. From code, use the sequencer endpoints in add email accounts to Instantly or Smartlead via API.
In Smartlead
- Copy the API key. Copy the API key from your Smartlead settings into the Outreach2day connection (api.smartlead.ai)
- Check the accounts. After the export the mailboxes are listed in Email Accounts as SMTP accounts (helpcenter.smartlead.ai)
- Or upload the CSV. Email Accounts > Add Account(s) > Connect Your Email Account, choose the file, check the preview for invalid rows and upload the valid ones (helpcenter.smartlead.ai)
- Set the daily cap. Open each account's settings and set the daily cap and the minimum time gap (helpcenter.smartlead.ai)
Fields in the Smartlead CSV
The file from the Smartlead export has these columns (the one-click export sends the same settings through the API):
| Column | Value |
|---|---|
from_name | Sender first and last name |
from_email | The mailbox address |
user_name | The mailbox address |
password | The mailbox password |
smtp_host | outreachmailstream.com |
smtp_port | 465 |
imap_host | outreachmailstream.com |
imap_port | 993 |
max_email_per_day | 20 |
custom_tracking_url | smartlead.<your domain> |
warmup_enabled | TRUE |
total_warmup_per_day | 20 |
daily_rampup | 5 |
reply_rate_percentage | 40 |
bcc | Empty |
signature | Empty |
different_reply_to_address | Empty |
imap_user_name | The mailbox address |
imap_password | The mailbox password |
- The 19 columns are the ones in Smartlead's sample CSV, in the same order
- max_email_per_day is 20 in the file; raise it to 25 after the ramp
- custom_tracking_url is filled with smartlead.<your domain>. Smartlead verifies it only when that subdomain has a CNAME to open.sleadtrack.com; add the record, or clear the column if you don't use tracking
- warmup_enabled TRUE turns on Smartlead's warm-up as well (the one-click export leaves it off). Outreach2day warm-up already runs, so set it to FALSE or keep Smartlead's numbers low: its help center suggests 10 to 20 warm-up emails a day with active campaigns and a 20 to 30% reply rate
Connection settings
To add a single mailbox by hand, or to check what Smartlead saved, use these settings:
| Field | Value |
|---|---|
| SMTP host | outreachmailstream.com |
| SMTP port | 465 (SSL/TLS) |
| IMAP host | outreachmailstream.com |
| IMAP port | 993 (SSL/TLS) |
| Username (SMTP and IMAP) | The full email address |
| Password (SMTP and IMAP) | The mailbox password from the export (the same for SMTP and IMAP) |
Sending settings per mailbox
- Mailboxes can send cold email 14 days after warm-up starts; warm-up keeps running after that
- Up to 25 cold emails per mailbox a day, warm-up not counted
- Start low on day 14 (for example 5 a day) and reach 25 around day 21
- To send more, add mailboxes and domains; keep the per-mailbox number at 25
Where to set it in Smartlead:
- Daily cap per mailbox (max_email_per_day in the CSV and API): set 25 for cold email. Smartlead's own guidance counts warm-up and outbound together in the cap (helpcenter.smartlead.ai)
- Minimum time gap per mailbox: Smartlead suggests 10 to 15 minutes, and a campaign interval at least 2 minutes longer than the account gap (helpcenter.smartlead.ai)
- Smartlead's Daily Ramp-Up applies to its warm-up volume only; ramp cold email by raising the daily cap in steps (helpcenter.smartlead.ai)
Why 25: how many cold emails one mailbox should send a day. The day-by-day ramp: email warm-up schedule.
Warm-up
Warm-up for Outreach2day mailboxes runs in Outreach2day and is included in the price. It keeps running after you export the mailboxes, whichever tool sends from them, so the other tool's warm-up is optional.
- Smartlead's warm-up settings: Enable Warmup, Total Daily Emails, Daily Ramp Up, Randomise Warmup Numbers, Reply Rate (helpcenter.smartlead.ai)
- With active campaigns Smartlead suggests 10 to 20 warm-up emails a day and a 20 to 30% reply rate (helpcenter.smartlead.ai)
Keep warm-up on while the mailbox sends: should I keep warm-up running while sending.
DNS and tracking domain
- SPF, DKIM and DMARC for every Outreach2day domain are set and checked automatically; you add nothing for sending
- A custom tracking domain is a CNAME on a subdomain of your sending domain. For a domain whose DNS Outreach2day hosts, add it in the app: Domains, open the domain, Manage DNS records, Add record (type CNAME). For a domain whose DNS stays at your registrar, add it there
- A tracking domain matters only with open or click tracking on. In the first cold email, leave out the tracking pixel and links and measure replies (see the answer on open tracking below)
- Smartlead's custom tracking domain is a CNAME with host emailtracking (or any subdomain) pointing to open.sleadtrack.com (helpcenter.smartlead.ai)
- Enter it as http://emailtracking.yourdomain.com under Custom tracking domain in the account, then click Verify CNAME after 30 minutes to 24 hours (helpcenter.smartlead.ai)
More on tracking: do open tracking and links hurt cold email deliverability.
Troubleshooting
| Error or symptom | Fix |
|---|---|
| Connection Timed Out | Smartlead's article suggests switching SMTP to port 587. Outreach2day mailboxes use 465 with SSL: keep 465 and check that the security setting is SSL and the host is outreachmailstream.com (helpcenter.smartlead.ai) |
| IMAP failure: invalid_grant | The server rejected the login: check the password and that the username is the full address. Export the mailbox again for the current password (helpcenter.smartlead.ai) |
| 550 5.4.5 Daily user sending quota exceeded | Lower the daily cap and lengthen the time gap; Smartlead says it often clears within 24 hours (helpcenter.smartlead.ai) |
| Account disconnected | Email Accounts > select the accounts > gear icon > Advanced Settings > (Re)connect Emails, or turn on Auto reconnect in the Outreach2day connection (helpcenter.smartlead.ai) |
| Authentication failed / invalid credentials | Use the full email address as the username and the password from a fresh export. A disabled mailbox is exported with an empty password, so it can't connect |
| Connection timed out or SSL/TLS handshake error | Use SMTP port 465 with SSL/TLS and IMAP port 993 with SSL/TLS, both on outreachmailstream.com. Check that the tool did not switch the security setting to STARTTLS or none |
| Mailbox connects but can't send yet | Check the mailbox in Outreach2day: new mailboxes are being set up for up to 24 hours, and cold email starts 14 days after warm-up starts |
| Mailbox disconnected after it worked | Reconnect it in the tool with the same settings. With a one-click connection (Instantly, Smartlead) and auto-reconnect on, Outreach2day reconnects it for you |
If bounces climb after the mailboxes connect, look at the list: why a cold email bounce rate gets too high.
FAQ
Is the Smartlead export included in the Outreach2day price?
Yes. Connecting Smartlead, exporting mailboxes, auto export and auto reconnect are included for every Outreach2day account at $2.50 per mailbox a month. You pay Smartlead for your Smartlead plan.
Why is Smartlead's warm-up off after the one-click export?
The export creates each account with warmup_enabled false, because warm-up for Outreach2day mailboxes runs in Outreach2day and keeps running after the export. You can turn Smartlead's warm-up on in the account if you want both.
How many mailboxes can I add to Smartlead?
Smartlead's pricing page says every plan includes unlimited email accounts; its connect article says the limit depends on the plan. Check Settings > Billing in Smartlead before a large export.
Can I send from Outreach2day instead of Smartlead?
Yes. Outreach2day has its own campaigns with steps, contacts, stats and a reply inbox. The Smartlead export is for teams that already run their campaigns in Smartlead.
Sources
Smartlead documentation, read on 2026-10-09. Menus and field names change; if a step differs, Smartlead's own page is the reference.
- Smartlead: Bulk add email accounts: helpcenter.smartlead.ai/en/articles/12-bulk-add-email-account
- Smartlead: How to connect your mailbox: helpcenter.smartlead.ai/en/articles/446-how-to-connect-your-mailbox-to-smartlead
- Smartlead: Email account disconnection reasons: helpcenter.smartlead.ai/en/articles/65-understanding-email-account-disconnection-reasons-in-smartlead
- Smartlead: Sending quota exceeded: helpcenter.smartlead.ai/en/articles/22-troubleshooting-sending-quota-exceeded-error
- Smartlead: Daily ramp-up in warm-up: helpcenter.smartlead.ai/en/articles/164-understanding-the-daily-ramp-up-feature-in-smartlead-s-email-warm-up
- Smartlead: Enable email account warm-ups: helpcenter.smartlead.ai/en/articles/52-how-to-enable-ai-email-account-warm-ups
- Smartlead: Custom tracking domain: helpcenter.smartlead.ai/en/articles/50-setting-up-smartlead-custom-tracking-domain-for-better-email-engagement
- Smartlead: Connection timed out: helpcenter.smartlead.ai/en/articles/43-why-am-i-getting-a-connection-timed-out-error
- Smartlead: IMAP failure invalid_grant: helpcenter.smartlead.ai/en/articles/142-understanding-imap-failure-the-invalid_grant-error
- Smartlead: Reconnect a disconnected account: helpcenter.smartlead.ai/en/articles/179-how-can-i-reconnect-my-email-account-if-disconnected
- Smartlead API: Create an email account: api.smartlead.ai/reference/create-an-email-account
