On Sun, Sep 7, 2008 at 10:31 AM, Gabri Mati <[EMAIL PROTECTED]> wrote: > I thought about making an smtpd listening on a non-default port accepting > clients for sending. What do you think about that?
Sounds like you're looking for port 587, the submission port, as described in RFC 4409. Protocol-wise, ports 25 and 587 differ in the following: 1) some SMTP extensions are banned from port 587 (ETRN), others are banned from port 25 (BURL, FUTURERELEASE) 2) the port 587 server is permitted to do additional message canonicalization that a port 25 is banned from. 3) many more ISPs filter outbound port 25 to cut down on spam generation by their customers As for authenticating the remote clients with dynamic IPs, why not use the standard SMTP AUTH extension? Lots of places use that to permit relaying by remote clients; indeed, the default sendmail configs do so. Do your remote clients not support that extension? Philip Guenther
