On 29 Jun 2016, at 9:57, mmgomess wrote:
Hi friends.
I need to limit the number of addresses in the "To:" in messages from
my
server domain users.
It is possible?
Yes. To limit based on the message "To:" header you would need either to
use header_checks or an external content filter. Note that this does not
prevent spamming, it merely prevents a rather careless form of spamming.
It is important to understand that the "To:" header is entirely
independent of the SMTP envelope recipients after a message has been
submitted to a MTA like Postfix. To limit the number of envelope
recipients per message is also possible in Postfix, but it is generally
not very useful to do so because the sender can simply send multiple
independent copies with fewer recipients each than whatever limit you
define for Postfix.
