For what it's worth, Pine's default polling interval is 150 seconds, and my old MailManager's default polling interval is 180 seconds. Neither program has ever encountered problems with NAT timeouts.
However, it does seem that using the IDLE extension will provoke a NAT timeout, so a client that implements IDLE should have a means to disable IDLE in favor of polling. -- Mark -- http://staff.washington.edu/mrc Science does not emerge from voting, party politics, or public debate.
