Hi, This problem is not caused by mailman, but I still want to give it a shot here. I'm hosting a mailing list on top of mailman3. Emails are supposed to be sent out by AWS ses. However, ses requires that sender address must be verified, which leads to a problem that emails sent by subscribers to mailing list cannot be sent to other subcirbers, since their addresses are not verified. And it is impossible to verified every subscriber. Are there smtp service providers allowing unverified email address to send out emails, or do I have other solutions?