KB08072101 Limiting the size of emailsMailtraq has several places where it is possible to control the size of emails that are handled.
Options | Incoming Mail
At [x] Limit the size of inbound mail
Options | Services | SMTP service - Abuse-tab
At [x] Enable Large Message Safety
Options | Services | HTTP service
At 'Maximum Data Upload'
Note that Mail Group Properties - Accounting can also affect how large messages are handled |