A “failed warmup” is when a mailbox in Smartlead cannot complete its scheduled warmup actions — sending or replying to warmup emails, because the system blocks it or skips it due to an error or unmet prerequisite. You’ll typically see no warmup sends for the day, errors in the account status, or the account marked blocked until fixed.
This guide helps monitor and troubleshoot your email warmup process by verifying key components.
Successful email warm-up requires a few critical technical checks to ensure your domain and mailbox are ready to build a strong sending reputation.
Confirm MX exists and points to your mail host. Missing or wrong MX breaks replies and can cause trust issues.
Our internal verifier checks MX, SPF, and DMARC continuously and logs pass or fail; use that signal to spot systemic DNS issues.
Ensure the mailbox is active and can receive mail. Send a test from another inbox and check for bounces. MX or disabled inbox will cause “not reachable” and stall warmup.
Check IMAP/SMTP or OAuth is actually connected and ports are correct. Providers like Google or Microsoft may require app passwords or IMAP enablement.
Confirm warmup is enabled for the account and the daily ramp is reasonable. Review the Overview to see if warmup emails were sent today and yesterday.
Investigate recent bounces and block events. Verify the domain and IP aren’t on blocklists and that SPF/DKIM alignment matches the From domain.
Go to the Email Account tab.
Click on the Mailbox Issue Found tab or use the filter icon to show Disconnected Mailboxes.
Select Skip Validation - Show All Issues
Click on the box with question mark icon and it will show the reason why the account was disconnected.
And click check solution button which will offer you the steps on how to fix it.
Q: What if my emails aren’t sending during warm-up?
A: Check mailbox connectivity and verify your IMAP/SMTP or OAuth settings. Also, confirm your DNS records are correct. Use the Smartlead dashboard to identify any disconnections.
Q: How long does warm-up typically take?
A: It depends on your starting volume and domain reputation but usually ranges from 2 to 6 weeks with gradual volume increases.
Q: Can I speed up warm-up by sending more emails faster?
A: No. Sending too many emails too quickly can hurt your reputation and increase the chance of blocks or spam flags.
Q: What should I do if my domain is on a blocklist?
A: Identify the reason for the block, fix any issues causing spam-like behavior, and request removal from the blocklist. Our support team can assist.
If you encounter any issues with email warm-up, DNS verification, or mailbox connectivity that you cannot resolve, please contact our support team. We’re here to help ensure your campaigns run smoothly and your emails reach the inbox.
