Just discovered today that a post notification of two weeks ago had stalled on subscriber number 74 out of nearly 800. It did so with the SMTP error pasted below.

MailPoet must not choke during a send. My subscribers receiving a two-week-old post is completely unacceptable. Suggest copying SMTP errors out to a log and then notifying the administrator if there are one or more SMTP errors encountered during a send.

Let me repeat: Choking off a send due to a simple SMTP error is completely unacceptable. It's positively amateurish.

Sending has been paused due to a technical issue with SMTP: SMTP Error: The following recipients failed: ****@avistar.aero: Requested action not taken: mailbox unavailable invalid DNS MX or A/AAAA resource record 1MpUtU-1wvhzx2PtM-00jusb Unprocessed subscriber: