SPF record for Mailchimp Transactional

Mailchimp Transactional sends application and transactional mail through the Mandrill API or SMTP. To send that mail as your domain and pass DMARC, publish the records below and check the alignment notes.

The SPF record

There is no include to put on your root record. When I checked on 4 Sep 2026, Mailchimp's Transactional documentation set a sending domain up with two DKIM CNAMEs and a DMARC record, and asked for no SPF mechanism of yours.

SPF is checked against the return path, and by default that address sits on mandrillapp.com. The pass belongs to Mailchimp and does not align with your From domain, so DMARC passes on DKIM alone until you move the return path onto a subdomain of your own.

Whatever you end up publishing, count the lookups afterwards. SPF allows ten DNS lookups across the whole chain of includes. Go over and receivers return a permerror, and SPF fails for every sender in the record. Our free SPF checker follows every include and gives you the count.

DKIM

Mailchimp holds the keys, and you point at them with two CNAMEs:

Publish both, then press Test DNS Settings against the sending domain. Older setups used one TXT record at mandrill._domainkey holding a key shared across accounts. If that is what your domain still carries, replace it with the pair above.

Return path and SPF alignment

A custom return path is one CNAME on a subdomain, pointed at mandrillapp.com. Mailchimp's documentation says it has to be a subdomain, never your root domain:

Add it under Settings, Tracking and Return Path Domains, then apply it on the Sending Defaults page or per message with the return_path_domain parameter. SPF is then checked against mail.example.com, which aligns with a From address at example.com under relaxed matching.

DMARC alignment with Mailchimp Transactional

DMARC passes when SPF or DKIM passes and the domain it authenticated matches the domain in your visible From address. A provider can pass both checks for its own domain while your mail fails DMARC.

• Mailchimp's campaign product and Mailchimp Transactional are separate, with separate records. Authenticating a domain in one does not authenticate it in the other.
• A tracking domain and a return-path domain are two different CNAMEs. Tracking changes the links inside the message and has no effect on DMARC.
• A return-path domain belongs to one Transactional account. Two accounts sending as the same domain need a subdomain each.

The DMARC alignment guide covers the general case, and the dmarc=fail page shows how to read the Authentication-Results header.

Verification

Substitute your domain, and run these after the TTL on anything you replaced has expired:

Then send one message through Mailchimp Transactional to a Gmail address you control, open Show original, and look for dkim=pass with your domain in header.i. A test message shows what a receiver does with your mail. A DNS lookup only shows what you published.

Our SPF checker gives you the lookup count. The DKIM checker shows whether a selector resolves and whether the key is long enough, and the DMARC checker reads your policy back to you. You can use them free, without an account.

I checked the values here against Mailchimp Transactional's own documentation, at Mailchimp Transactional documentation. Providers change their DNS requirements without much notice. If their screen shows something different from this page, follow their screen and tell us.

A record can be correct and still fail alignment once real mail goes through it. Receivers record that result in the reports they send. We read the reports for you, and on a paid plan we email you the day a new sender fails. See whether this sender passes. Your first domain is free.