One of our clients reported that he suddenly stopped receiving emails from gmail.com. After investigation, we discovered the cause: he had added a block for the domain mail.com in Spam Filters → Block by Domain.
Contrary to what the interface suggests ("Block by Domain"), the generated filter does not perform an exact domain match. Instead, it uses a simple substring search on the From: header:
Because of this, any address containing the string mail.com anywhere is blocked — including [email protected], [email protected], [email protected], etc.
Expected behavior:
The "Block by Domain" option should block only exact domain matches (e.g. [email protected]), not partial strings.
1. Simple fix:
Probably the simplest fix would be adding @ to the searched string, eg:
2. Better solution:
Block both the From header and the envelope sender (MAIL FROM) eg:
Contrary to what the interface suggests ("Block by Domain"), the generated filter does not perform an exact domain match. Instead, it uses a simple substring search on the From: header:
Code:
if
$header_from: contains "mail.com"
then
seen finish
endifBecause of this, any address containing the string mail.com anywhere is blocked — including [email protected], [email protected], [email protected], etc.
Expected behavior:
The "Block by Domain" option should block only exact domain matches (e.g. [email protected]), not partial strings.
1. Simple fix:
Probably the simplest fix would be adding @ to the searched string, eg:
Code:
if
$header_from: contains "@mail.com"
then
seen finish
endif2. Better solution:
Block both the From header and the envelope sender (MAIL FROM) eg:
Code:
if
$header_from: contains "@mail.com"
or
$sender_address_domain is "mail.com"
then
seen finish
endif