E-mails not going out

[A15]

I have this weird problem were e-mails don't reach their destination.....
The user sends an e-mail for example to a yahoo account and there is no problem the e-mail goes to yahoo!
BUT same user emails a hotmail account and the e-mail does not go through!!
I have checked my servers ISM and there is nothing in the queue....

I don't get any error messages, no bouncing admin e-mails
....I can ping my DNS on the Exchange server....

Any help would be appreciated....

 

[mnewell]

No NDR's back? Weird. Anything in the MTA queue?

What do you see if you a lookup for hotmail from the exchange server?
Also, I believe Hotmail does a reverse DNS lookup on incoming email, is the DNS MX records for your zone setup?

 

[A15]

MTA is empty.....

The DNS is fine ..I have no problems receiving e-mails...
its when I reply or send out....that this thing happens....

 

[A15]

Lookup for hotmail: (from exchange server)


Non-authoritative answer:
hotmail.com MX preference = 5, mail exchanger = mx1.hotmail.com
hotmail.com MX preference = 5, mail exchanger = mx2.hotmail.com
hotmail.com MX preference = 5, mail exchanger = mx3.hotmail.com
hotmail.com MX preference = 5, mail exchanger = mx4.hotmail.com

hotmail.com nameserver = ns1.hotmail.com
hotmail.com nameserver = ns2.hotmail.com
hotmail.com nameserver = ns3.hotmail.com
hotmail.com nameserver = ns4.hotmail.com
mx1.hotmail.com internet address = 65.54.254.129
mx1.hotmail.com internet address = 65.54.166.99
mx1.hotmail.com internet address = 65.54.252.99
mx2.hotmail.com internet address = 65.54.254.145
mx2.hotmail.com internet address = 65.54.166.230
mx2.hotmail.com internet address = 65.54.252.230
mx3.hotmail.com internet address = 65.54.253.99
mx3.hotmail.com internet address = 65.54.254.140
mx4.hotmail.com internet address = 65.54.254.151
mx4.hotmail.com internet address = 65.54.253.230

 

[mnewell]

Looks like DNS is good.

I asked about your DNS setup because some email systems, hotmail include, will block your email from coming in if the DNS for your system doesn't match what is on the email.

For instance, (just making up numbers) if your server sends email out and say your firewall NAT's everything out on 222.222.222.222, but your server is at 222.222.222.111 and your MX record in your zone points to 222.222.222.111 it will reject your message as spam.

Also, have you checked if your domain is on a RBL list somewhere?

http://www.dnsrbl.com/lookupserver.jsp

Weird though, in either of these scenarios you should be getting NDR's back.

If there's nothing in you MTA or IMS queue it sounds like the mail is getting out OK.