I've been running a RH server since 7.1 and generally everything works out great, one of my HDs fried recently so I decided to reinstall with Fedora, I've gotten the server back up and running on all fronts except mail, its not quite working. First off, my firewall is blocking my SMTP port so I can't currently _receive_ mail from outside my server but I'm aware of this problem and will be fixing it shortly. What is stumping me is that I can't send mail to certain domains _from_ my server, it either times out or is refused:

Feb 6 10:27:46 domain sendmail[18536]: j15KvUHl013820: to=<account@gmail.com>, ctladdr=<user@domain> (500/500
), delay=21:30:16, xdelay=00:03:00, mailer=esmtp, pri=2011505, relay=gsmtp57.google.com. [216.239.57.27], dsn=4.0
.0, stat=Deferred: Connection timed out with gsmtp57.google.com.

Feb 8 07:24:46 domain sendmail[20081]: j18EOvHl020075: to=<user@domain.org>, ctladdr=<user@domain.net> (500/500), delay=00:59:49, xdelay=00:00:00, mailer=esmtp, pri=121546, relay=mxpool.postoffice.net. [165.212.6
5.113], dsn=4.0.0, stat=Deferred: Connection refused by mxpool.postoffice.net.

But to users at other domains the mail gets sent fine. Why would it only fail on sending to some domains, is it a problem with my DNS?

Any help is much appreciated,
Thanks!

Ok, found the fix to allow me to access port 25 from outside my box, and thats now working but I still can't send mail to certain addresses, gmail.com for example.

EDIT:
After more reading it looks like it might be related to my /etc/hosts file which currently reads:

# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 myname.net myname localhost.localdomain localhost


What should I add to this, not all websites agree, but something in the form of:

myipaddress myname.net myname.net(which is what HOSTNAME is)