Cannot send email to remote office

[dips00]

Hi,
We have office1 with exchange 2003 and office2 with exchange 5.5.
Office2 is able to send email just fine to office1 but office1 cannot send or reply to an emails from office2. This connectivity has been working fine for the past couple of months till last thursday. We are not sure what could have chnaged. Thanks for the insight.

 

[wfbtr]

Is any mail getting to Office 2, from any other source besides Office 1? And is there a VPN involved?

 

[dips00]

Hi wfbtr,
we do get email from external sources and other companies to office2 just fine. Its just email from office1 that does not arrive to office2. No vpn, just a t3.
thanks.

 

[PuzzledUNIX]

Check your DNS records, contact ISP provider check if you have forwarders set up or not, check reverse DNS entry on ISP end if you have undeliverable messages. Most of the time if no evidence of anything, more likely DNS or something blocking outgoing packets (A-virus, Group shiled services if stopped, etc...)

Check and let me know...

 

[wfbtr]

could it be blocked by a change in a filter on either end- ie: scanmail/emanager?

also, is this a parent/child domain?

 

[PuzzledUNIX]

slim chance (check just in case), check if any automated updates got downloaded and installed on exchange boxes without your notification(like netframe, device level, etc...). In parent/child make sure you have SMTP connector setup on parent and recepients policy as well).

I hope we will nail this...

 

[dips00]

FYI:
It turned out that the IP address for Office2 that Office1 was using was incorrect. They were sending it to x.x.x.21, whch is a half built exchng2k3 box (no emails prccssng yet). So no emails via our connectors were getting delivered to our 5.5 box. That also explains why email from and to outside was just fine sice they don't use that connector.
Thanks all for your help.