Relaying denied. IP name lookup failed

We are getting the following error from our Exchange 5.5 server:

----- The following addresses had permanent fatal errors -----
<jason.lavetan@cooperbooth.com>
    (reason: 550 5.7.1 <jason.lavetan@cooperbooth.com>... Relaying denied.
IP name lookup failed [xxx.xxx.xxx.xxx])

   ----- Transcript of session follows -----
... while talking to cooperbooth.com.:
>>> DATA
<<< 550 5.7.1 <jason.lavetan@cooperbooth.com>... Relaying denied. IP name
lookup failed [xxx.xxx.xxx.xxx] 550 5.1.1 <jason.lavetan@cooperbooth.com>...
User unknown
<<< 503 5.0.0 Need RCPT (recipient)

It just started happening over the weekend.  We can send internal email fine, and outgoing mail is working fine, just not incoming.  It seemed to have happened after we did our end of month server reboots this past Friday.

Anyone have any ideas?  
LVL 1
jlavetanAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

 
jlavetanAuthor Commented:
Actually I answered this myself....

It was a screwed up MX record... I already knew about what the article describes.  Our server is setup not to relay.

We simply had to fix the MX record.  Problem Solved :-)
0
 
RomModCommented:
The question has been PAQ'd and the 100 points have been refunded.
RomMod
Community Support Moderator
0

Experts Exchange Solution brought to you by ConnectWise

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.