7.38. ( SMTP Relay ) - Internal MASQed computers cannot send SMTP or POP-3 mail!
Though this isn't a Masquerading issue but many users do this so it should be
mentioned.
SMTP: The issue is that you are probably using your Linux box as an SMTP
relay server and get the following error:
"error from mail server: we do not relay" |
Newer versions of Sendmail and other Mail Transfer Agents (MTAs) disable
relaying by default (this is a good thing). So do the following to fix this:
Sendmail: Enable specific relaying for your internal MASQed machines by editing
the /etc/sendmail.cw file and add the hostname and domain name of your internal
MASQed machine. You should also check to see that the /etc/hosts file has the
IP address and Fully Qualified Domain Name (FQDN) configured in it. Once this
is done, you need to restart Sendmail for it to re-read its configuration
files. This is covered in
TrinityOS - Section 25
POP-3: Some users configure their internal MASQ'ed computer's POP-3 clients to
connect to some external SMTP server. While this is fine, many SMTP servers
out there will try to IDENT your connection on port 113. Most likely your
problem stems around your default Masquerade policy being set to DENY. This is
BAD. Set it to REJECT and re-run your rc.firewall-* ruleset.