Nope, they're sent via Amazon PHP SDK client.Do "Please validate this server" messages for amazon ses web api get sent through swiftmailer and phpmailer?
Actually nothing changed at all afaik. Have you tried to play around with the FORCE FROM option in the delivery server?What changed from the previous version to the new version for amazon web api?
See the force from option as i said above, maybe this is what causes the issues.Btw, when I send a test email from within campaigns, it's also properly signed. Any ideas?