Not receiving some large emails on my Mac

[jimmys girl]

I am not getting large e-mails on my Mac at the office, yet they show up on my Mac at home. Both are Mac Minis running 10.5, both served by the same internet provider and of course the same mail server. There is a high volume of email on my account. Occasionally it comes to my attention a very large one has not made it to my office. The internet provider has no idea why. The mail server says there must be a filter on the Mac in the office that does not exist on the Mac at home. Is there possibly a setting on the one computer limiting the size of files coming into my MacMail? Any ideas?