Outlook dropped for exceeding max decompression layer limit

[Keanman]

Hi guys and gals,

I'm trying to find a solution for a problem for a friend who cannot recieve emails with attachments. They get the email with this error and no attachment (the ips are masked for obvious reasons):

"Your mail 999.999.999.999:9999->999.999.999.999 is dropped for exceeding max decompression layer limit"

They are using outlook 2003. The only thing I can find on this issue is concerning multiple zip files with either AV software or a Netscreen. The attachments are not zipped so that rules both of those resolutions out.

Any light that can be shed on this issue would be greatly appreciated. Post any further questions if needed.

Thanks