Remove OR Replace "mailed by" field with DKIM & SPF enabled in AWS SES

You can replace mailed-by: us-west-2.amazonses.com with mailed by: sub.example.com but not with mailed-by: example.com.

In other words, unnaked domain (with subdomain) like sub.example.com is possible but naked domain like example.com is impossible to replace with us-west-2.amazonses.com for mailed-by.

To replace us-west-2.amazonses.com with sub.example.com for mailed-by, you must create a custom MAIL FROM domain.

The below is how you create the custom MAIL FROM domain sub.example.com.

Click on the domain example.com.

Then, the detail is shown.

Then, click on MAIL FROM Domain to show Set MAIL FROM Domain button.

Then, clicking on Set MAIL FROM Domain button, the window is open.

Then, put the subdomain "sub" to the field and click on Set MAIL FROM Domain button.

Then, the MX Record and SPF Record are shown. You must add the MX Record and SPF Record to Route 53 in addition to the records of the domain example.com to verify the custom MAIL FROM domain sub.example.com.

Finally, check if the custom MAIL FROM domain sub.example.com is verified under MAIL FROM domain section.

If MAIL FROM domain status is still pending verification, click on retry in blue.

Then, it will be verified.

After the custom MAIL FROM domain is verified, mailed-by is sub.example.com whether or not you send emails using example.com or sub.example.com and whether or not your account is in the sandbox.

The mailed-by header is the usually used to persist the content of the envelope from or MAIL FROM through forwarding. Amazon do not allow the MAIL FROM to be customised. The following quote is from an Amazon employee in a comment on an blog post about SPF & DKIM:

The headers you mentioned [mailed-by] seem to be something appended by an ISP after the message left Amazon SES, rather than standard message headers. We unfortunately do not have control over receiver add-ons.

Nevertheless, assuming that the “mailed-by” value is based on the MAIL-FROM, the answer would be that right now all emails sent through Amazon SES have amazonses.com (or a subdomain of that) as the MAIL-FROM domain. We don't currently support its customization

Posted by Adrian@AWS on November 4, 2014 8:31:29 AM PST