[K12OSN] postfix problem ,dns maybe ?

[Barry Cisna]

Hello All,

  Not sure what caused this( like everything network gone wonky related),
but yesterday our school mailserver freaked out with the HD running
solid by the time i got several phone calls from teachers" Email is
down". Last I looked this server had been up for 125 days,and also on
our lan had one of our best/main servers that houses financial stuff had
frooze solid(MS Windows).Anyways after rebooting the mail server
FC3/K12LTSP 4.2.1 now whoever trys to send getting the below message
from emails that are sent externally to our mail server. can send out
fine and send/receive internally fine. This is the first trouble with
this server in two years running rock solid. ( seems I always read
this),,,:)
I've read several posts in the past about email server "loopbacks" but
have never run into this myself. I can not see anything wonky in the
postfix main & master config files. Seems like a dns thing but I cant see
what I need to see to resolve it.
When I look at "veiw full headers", of a bounced back/externally sent
message I see one thing changed: It used to show
emailhostname.school.domain  Now I'm seeing mail.school.domain -Almost as
though maybe our local stats dns provider may have changed something? I'll
call them Monday.

Postfix
Dovecot
amavisd
Squirrelmail
 Any ideas welcome.

Thanks,

Barry Cisna
westcentral school






 ----- Transcript of session follows -----
554 5.0.0 MX list for our.school.domain. points back to
mail.our.school.domain
554 5.3.5 Local configuration error
550 5.1.1 postmaster... User unknown