OS/2 Sendmail (was: Mail store and forward gateway setup)

[John Thompson]

On Sun, 28 Nov 1999 16:28:47 -0500 (EST), Wilson Rook wrote:

>When you say IBM send mail does not support relay, 
>what is this based on.  

The anti-relay directives were first implemented with sendmail v8.9.x; the
IBM version of sendmail is based on sendmail 8.6 and would not how how to
interpret the anti-relay rules.

>Even if you can not block relay outright, could you filter for approved 
>IP address and valid local domains?

In linux there is a nice package called "tcp_wrappers" that does this:
instead of inetd invoking the requested service directly it calls the
tcp_wrapper program, which compares the requesting address with a list of
approved/denied addresses and either invokes the requested service or
refuses the connection. This isn't perfect; it is still subject to
breaching by address spoofing and in any case, it is not usually
recommended to have inetd start sendmail anyway as a busy mail server can
easily get bogged down with this extra processing.  Finally, I'm not aware
that tcp_wrappers is available for OS/2 yet anyway.



John (john.thompson@attglobal.net)