MAILS GETTING BOUNCED BACK (localhost.localdomain does not exists)

chrlsquincy · 01-22-2010, 12:23 AM

We've had this server running before but two hours ago there are some domains outside which we cannot send email to.

this is a sample of the message we get

Quote:

The original message was received at Fri, 22 Jan 2010 14:31:59 +0800
from [10.0.200.10]

----- The following addresses had permanent fatal errors -----
<beth@nippon-antennaphil.com>
(reason: 550 localhost.localdomain does not exist)

----- Transcript of session follows -----
... while talking to nippon-antennaphil.com.:
>>> DATA
<<< 550 localhost.localdomain does not exist
550 5.1.1 <beth@nippon-antennaphil.com>... User unknown
451 4.4.1 reply: read error from nippon-antennaphil.com.

Our server's been running smoothly before but i dunno what happened.
I'm a newbie here so i really don't know what's been causing this.

Thanks in advance!

---------------------------------------

I can send mails to gmail and yahoo as well... but there are like 3 domains which we cannot send mails to.

chort · 01-22-2010, 12:39 AM

Your MTA is sending a HELO/EHLO string of localhost.localdomain . That's wrong. You need to configure it to send it's fully-qualified domain name. You should also have an A record in public DNS for that hostname, and the IP it points to should have a PTR record that points back to the A record. Failing any of those steps will result in a lot of sites blocking your mail.

chrlsquincy · 01-22-2010, 12:56 AM

Thanks!! but how do i change it? is it on sendmail?

and yes we do have a registered domain.

chort · 01-22-2010, 01:08 AM

Edit /etc/mail/sendmail.mc

Code:

O HeloName=hostname.mydomain.tld

Then do service sendmail restart

chrlsquincy · 01-22-2010, 01:30 AM

there's no such line in my sendmail.mc
but i added it at the bottom dnl HeloName=mydomain.etc
restarted sendmail
but my mails still get bounced back....

chort · 01-22-2010, 01:40 AM

I don't believe it will pick it up with dnl in front of it. Copy and paste exactly what I put in the code block, then just change the FQDN to match yours.

chrlsquincy · 01-22-2010, 02:43 AM

It says header Syntax error, line "eloName=hst.com.ph" when i restarted the sendmail.

chort · 01-22-2010, 03:14 AM

Hmm, here is what's in my sendmail.mc with the line before and after:

Code:

dnl #
O HeloName=pps-01.smtps.net

(the line below it is blank)

Perhaps you need dnl at the end of the previous line? M4 always drives me nuts. I wouldn't use Sendmail except that it's bundled with the product my company sells. I use Postfix on all the e-mail servers I build from scratch.

chrlsquincy · 01-22-2010, 04:18 AM

Thanks for really helping me out Chort...

works fine now when i placed exactly what you got right there...

**i place our domain though