Have a pop3 hosted mail- we never receive some emails

[carlosmarin2121]

We have a outside host that is hosting our pop3 mail- and have an issue that is driving me crazy-
we dont get some emails with attachments- If I send the same email to four users- one would get it and the other one does not-
sometimes people dont get emails at all- I log on the dashboard of the pop3 and dont find the message there- not even on the junk mail-
what could be causing this?
I have a Sonic Firewall NAS240- but i don think that it is blocking our emails- our ISP has informed me that it does not block emails with attachments...
everyone is running Outlook 2007 running Avira AV on all pc's- and on our Domain server (windows 2000 srs)

Thanks

 

[MakeItSo]

Have you checked the SMTP log?
What does it say?
Might be a greylisting problem.

[navy]"We had to turn off that service to comply with the CDA Bill."[/navy]
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