Troubleshoot the Opt-in Confirmation Email

When your audience is double opt-in, everyone who signs up will receive a follow-up email with a confirmation link to verify their subscription. If a newly subscribed contact doesn't receive the opt-in confirmation email, there are a few things that could be happening.

In this article, we'll go over some common issues with confirmation emails and give you some tips to help you troubleshoot.

Beginning February 2024, Gmail and Yahoo will require a custom authentication and a published Domain-based Message Authentication, Reporting & Conformance (DMARC) record for anyone sending more than 5,000 emails to Gmail or Yahoo addresses in a 24-hour period. To prevent your emails from bouncing, we strongly recommend authenticating your email domain and configuring DMARC.

Also, if you use a free email service like Gmail or Yahoo for your From email address, we strongly recommend you switch to an email address from a private domain, like the one you use for work or for your website.

For more information about custom authentication and DMARC, check out About Email Domain Authentication.

How long has it been?

Email delivery times vary depending on server traffic, so don't assume something is wrong if one of your subscribed contacts got their confirmation email instantly and one didn't. We recommend waiting a few hours before you do additional troubleshooting or seek support.

What email address did they use?

Sometimes, there are problems with the receiver's email server.

• If the subscribed contact signs up with a corporate email server, there could be an issue with their company's filter, firewall, or server. Test your forms with an external test account like Yahoo, Hotmail, or Gmail. If you get the confirmation email at those accounts as expected, it may be a corporate email server problem.
• When you send to an AOL, Yahoo, or Gmail account, give it more time. Some webmail programs delay delivery of bulk mail for up to 24 hours.
• If your subscribed contact uses a Gmail account, there's a chance the confirmation email may be placed in Gmail's Promotions tab. Ask your subscribed contact to add you to their contacts list to ensure your future emails are placed in the Primary tab.
• Your email could be caught in an aggressive spam filter. Ask the subscribed contact to check the junk folder.

What email address do you use?

Mailchimp sends an email on your behalf during the opt-in process, which could cause problems depending on how your email server is set up.

• If your email address is on a corporate domain, check with your IT group about what kind of filtering is set up. The server may ban emails from outside servers (like Mailchimp) that claim to be coming from your company (like if you put your company name in the "From" field).
• Spam filters sometimes block delivery of emails from new sources, or senders that aren't added to a allowlist (other providers may refer to it as "whitelist") as a trusted sender.
• If it's an email server issue, ask your subscribed contact to allowlist Mailchimp.

Is the signup form working as expected?

If no one receives confirmation emails and you ruled out a server issue, there could be something wrong on your signup form.

• If you use an embedded form, make sure the embedded form code was copied correctly into the website. When in doubt, copy the code from Mailchimp again, paste it into your site, and refresh the page before you test the form again.
• If this doesn't solve the problem, there could be a JavaScript or CSS conflict on your signup form page. This is common when multiple signup forms are displayed on a single page. To work around this, we recommend the Unstyled embed form or separating your forms so they appear on their own webpages.
• If you host your own signup forms, make sure all your audience fields are matched correctly and that you correctly updated the form action code.