email from message labs timing out

[Paddyo]

Hi

I have a strange problem receiving email from people using the message labs service. Every mail sent by them is timing out. The smtp log shows the ehlo, mail ,rcpt with 250 responses. After a while I get the timeout and the quit.

I have tried all of the usual, removing the virus protection software, the firewall is ok, exchange has been removed and reinstalled and now I am stuck.

Has anyone come across this before or does anyone have any suggestions.

Any questions please ask.

Thanks is advance

Paddyo

 

[Orenf]

How odd...

Have you seen this problem from people using similar services, such as Frontbridge or Electric Mail?


Oren

 

[Paddyo]

Hi Oren

I solved the mystery. It had nothing to do with messagelabs - although it did effect all of their mail.

On the firewall the MTU setting was 1500, whereas on the router the MRU setting was areound 1472. I set them both to be equal and everything started working - obvious or what!!!

Paddyo