Getting Started with Sendmail on MPE/iX 7.5

Solution Symposium Page 35April 4, 2002
firewall issues
•the #2 sendmail problem!
•your 3000 needs to query port 53
on DNS servers to resolve the
destination mail server hostname
•your 3000 needs to receive DNS
query answers
•your 3000 listens on its port 25
for incoming e-mail
•your 3000 needs to connect to
port 25 on destination mail servers
•does your firewall allow your
3000 to talk to the Internet?
•does your firewall allow the
Internet to talk to your 3000?
•firewall blocking results in
connection refused, timeouts, or just
no activity!