[TriLUG] sendmail and roadrunner

[Greg Brown]

Is anyone out there using their primary roadrunner machine (i.e. the one with 
the "live" IP address) as a mail relay host?  Most domains accept my mail 
just fine but others (xo.com, aol.com most noteably) reject my mail returning 
some version of the following error:

... while talking to triton.xo.com.:
>>> MAIL From:<greg at paloverde.nc.rr.com> SIZE=866
<<< 501 5.1.8 <greg at paloverde.nc.rr.com>... Sender domain must exist

I imagine this is due to roadrunner not adding my host name, paloverde, to 
DNS when it assigns the IP address.  So, the question becomes is there any 
way to fix this so I can mail my partents at their AOL address using my 
machine (paloverde) as a mail router?  And, just in case anyone is worried, I 
am an avid anti-spammer and I'm not trying to use my machine to spam.

I am running RH 7.1 and I checked the /etc/mail/sendmail.mc file but I can't 
see anywhere in the file where I can fix this problem.

Any help would be greatly appreciated.

Thanks!

Greg