Problem

SMTP 4.4.1 Error when sending an email, What does it mean?

Solution

SMTP 4.4.1 Error message indicates the recipients host is not responding.

This could be due to a temporary issue with thier network or mail server.  Typically the message will sit on the "deferred mail queue" and wait a period of time before trying to deliver the email again.  After several attempts to deliver the email, if not successful the message will fail and generate a postmater delivery failure message to the sender.

We recommend resending the email as it's possible the issue is transient.

If the email continues to bounce back you should then consider contacting the recipient to update their contact information.