Error: "550 5.7.1_ETR Mailbox disabled, not accepting messages" after emailing a TechMail address


Symptoms

You may receive the following message when attempting to send an email to a TechMail address:

Mailbox disabled, not accepting messages

Status code: 550 5.7.1_ETR

exampled screenshot

Cause

The TTU account associated with the TechMail address is disabled.

Resolution

The owner of that TechMail address will need to contact IT Help Central to get assistance with re-enabling the account.