MX record pointing to different IP and rejected mails

[guybrushtw]

Hi all:

I have searched the forums, but can't seem to find a suitable answer. This is mi case:

Our domain lives in a dedicated server at a hosting company, with IP 62.xx.xx.87.

Recently we changed the MX record to point to our Exchange server, in our company. We have an external fixed IP given by an ISP: 213.xx.xx.117.

Everything is fine, except for some domains, which reject our mail:

2007-04-26 06:57:33 194.x.x.80 OutboundConnectionCommand SMTPSVC1 - MAIL FROM:<[email protected]> 0
2007-04-26 06:57:33 194.x.x.80 OutboundConnectionResponse SMTPSVC1 - - 550+5.7.1+Access+denied 0

However, if I try to send that same mail from the hosting company IP via telnet to port 25, it works perfectly.

I've been reading about it, and I guess we should have a PTR record for the Exchange server. Is that right? How can I set it? Should it be written in the DNS zone in our dedicated server, pointing to the IP given by our ISP?

This is my current DNS table:

$TTL 86400

@ IN SOA ns.domain.com. a.a.a. (
1164006442 ; Serial
10800 ; Refresh
3600 ; Retry
604800 ; Expire
3600) ; Minimum

domain.com. IN NS ns.domain.com.
domain.com. IN NS dns1.domain.com.
domain.com. IN NS dns2.domain.com.
ns.domain.com. IN A 62.xx.xx.87
domain.com. IN A 62.xx.xx.87
webmail.domain.com. IN A 62.xx.xx.87
mssql.domain.com. IN A 62.xx.xx.87
sitebuilder.domain.com. IN A 62.xx.xx.87
mail.domain.com. IN A 213.xx.xx.117
dns1.domain.com. IN A 62.xx.xx.88
dns2.domain.com. IN A 62.xx.xx.89
exchange.domain.com. IN A 213.xx.xx.117
ftp.domain.com. IN CNAME domain.com.
www.domain.com. IN CNAME domain.com.
lists.domain.com. IN CNAME domain.com.
domain.com. IN MX 10 mail.domain.com.


TIA and best regards,

Javi.