I am sending out a newsletter and now I have thousands of error messages like:
EDIT: I had to lift amazons sending limits. Then it should work. This issue is not related to xenforo.
Zend_Mail_Protocol_Exception: Email to firstname.lastname@example.org failed: No connection has been established to email-smtp.eu-west-1.amazonaws.com - library/Zend/Mail/Protocol/Abstract.php:319