mouss pisze:
if all outbound mail goes via your server, you can use "poorman BATV".
for example: use smtp_generic to rewrite j...@example.com to say
joe+bou...@example.com, where '+' is your extension delimiter.
then you can reject mail from the null sender if it is not sent to a
/\+bou...@example\.com$/ address.
but if your users can send via other servers (ISP, hotel, ...), then you
can't use this to block like this. but you can use it as whitelist
mechanism, and implement aggressive checks if the recipient doesn't
match the +bounce extension (I'm talking about null sender case of course).
So far so good. Users of our mailserver are allowed to send only via our
mailserver (which hosts
webmail service for use wherever SMTP port is firewalled).
Another problem here is that some mailing-list managers use the envelope
sender to validate subscription.
Note that the +bounce address is replay-able. I'm not sure this is an
issue. if so, a cron job could update the extension on
daily/weekly/monthly basis...
I'm not sure if I fully understand. If I would not change "+ext"
extention in time, this wouldn't be a problem
for mailing lists? But then some users are using address books and
eventually they would remember
email address with extension. If those statements are true, then this
solution is quite bad for me.
Thank you for clarifying my mistakes
Pawel Lesniak
