[colug-432] Strange sendmail issue on Fedora 15

[Stephen Potter]

I'm suddenly having a strange issue with sendmail on my Fedora 15 home 
server.  This system has run F15 since soon after F16 released (I tend 
to stay one rev back to make sure I don't hit any new release problems), 
and this problem has only cropped up in the past couple of days since my 
last reboot.

When I send mail from my Windows client (Thunderbird), it takes several 
seconds for the outgoing message window to close.  The mail then enters 
sendmail's queue and gets a host name lookup error for my smarthost 
(smtp-server.insight.rr.com).  If I do nothing, it will stay in there 
and after 4 hours I'll get a delayed warning email. If, however, I go 
onto the server and run sendmail -q, the message will send without 
problems.  I also see this same issue if I am using Openwebmail.  
Incoming mail works without issue, however.

It shows all the signs of a DNS issue, but I've checked that my 
resolv.conf still lists the Google 8.8.8.8 server, and nslookup/dig all 
work fine.  Plus, like I said, if I run sendmail by hand everything 
clears without issue.

Anyone have any thoughts?

Thanks,
-spp