[afnog] is my sendmail an open-relay?

[Joe Abley]

On 10-Dec-2006, at 17:16, Andy Davidson wrote:

> Running a private (and locked down) smtp server on tcp/80 may well
> get you round even more firewalls.. Running a private OpenVPN system
> on tcp/80 may well be even more useful.

tcp/443 is a better bet, much of the time. There are many  
environments in which tcp/80 is transparently redirected to caches,  
and when the client doesn't talk HTTP, unpredictable things may happen.

Since HTTPS (tcp/443) involves SSL/TLS, which itself involves end-to- 
end exchange of certificates, it's less likely to be interfered with.


Joe