How can limit the number of recipients in a single message?

[kaelthasmanu]

Hello
Is there an option in proxmox mail gateway to limit the number of recipients in a single message? I've searched but I can't find it

 

[kalachev_89]

Hello.
You can do that via postfix manual config.
Postfix has smtpd_recipient_limit parametr, that default is 1000. So you need via postfix template reduce to your limit.

 

[kaelthasmanu]

Hello.
You can do that via postfix manual config.
Postfix has smtpd_recipient_limit parametr, that default is 1000. So you need via postfix template reduce to your limit.

Hello friend, I tried the solution that gave me adding that parameter to main.cf.in and it didn't work for me, I don't know if I did it wrong

 

[kalachev_89]

Hello friend, I tried the solution that gave me adding that parameter to main.cf.in and it didn't work for me, I don't know if I did it wrong

Yes, it isn't work as expected.
So you can try block this e-mail via spamassassin like in this topic
You can add to file/create file /etc/mail/spamassassin/custom.cf

header __COUNT_RCPTS To =~ /(?:[^@,\s]+@[^@,\s]+)/
tflags __COUNT_RCPTS multiple
meta RCPTS_10_PLUS (__COUNT_RCPTS > 10)
describe RCPTS_10_PLUS block e-mail with more, than 10 recipients
score RCPTS_10_PLUS 2

and after reload smtp filters

systemctl reload pmg-smtp-filter

This rule wll add score 2 to e-mail with more than 10 recipients.

So custom rule with high spam score (30+) and mail filter to block e-mail with high spam score (30+) will block incoming e-mails with high count of recipients.

 

[kaelthasmanu]

Yes, it isn't work as expected.
So you can try block this e-mail via spamassassin like in this topic
You can add to file/create file /etc/mail/spamassassin/custom.cf

header __COUNT_RCPTS To =~ /(?:[^@,\s]+@[^@,\s]+)/
tflags __COUNT_RCPTS multiple
meta RCPTS_10_PLUS (__COUNT_RCPTS > 10)
describe RCPTS_10_PLUS block e-mail with more, than 10 recipients
score RCPTS_10_PLUS 2

and after reload smtp filters

systemctl reload pmg-smtp-filter

This rule wll add score 2 to e-mail with more than 10 recipients.
View attachment 48600
So custom rule with high spam score (30+) and mail filter to block e-mail with high spam score (30+) will block incoming e-mails with high count of recipients.

thank you very much friend it worked for me that way