> I believe you need to move your users to the alternate submission port. The > normal widely used port for this is 587. Some people will lock down port > 587 to only allow authenticated and encrypted connections. Others will > allow non crypto, but mandate authentication.
Thanks for the suggestion. It seems to be indeed the "right" thing to do. I hope that ISP will not start intercepting also port 587 :-) > Switch your users to port 587, assuming you have set up the submission port > in master.cf and you should be good to go. I suggest also enabling TLS as > well. That's what I've done. Actually I will try to enforce TLS I modified master.cf and configure submission that way: submission inet n - n - - smtpd -o smtpd_enforce_tls=yes -o smtpd_sasl_auth_enable=yes -o smtpd_client_restrictions=permit_sasl_authenticated,reject Regards, Gaël