SMTP error X.7.16
Message too big for specified priority
Updated Jul 1, 2026
The short answer
Message too big for specified priority Common cause: Size exceeds the limit for that priority class
Quick fix
Reduce size, raise priority if appropriate, or retry later
This code is written X.7.16 because the reason is the same whether the failure
is temporary (a 4 first digit) or permanent (a 5). Read the first digit of your
own bounce to know which applies.
How to fix it
Reduce size, raise priority if appropriate, or retry later