Google Message Security for Google Apps Administration Guide - Manual (Page 283)

Attachment Manager 283
How do you limit file size of attachments?
Set the maximum attachment size using the Message Size filter as described in
“Message Size Filter” on page 280.
Does Attachment Manager filter viruses?
No, messages and attachments are scanned for viruses before they pass through
the Attachment Manager filter. Any messages with viruses are disposed of before
reaching attachment filters.
Why is a message in an user’s quarantine when it should have been sent to the
admin’s quarantine (Quarantine Redirect) or blocked by Attachment Manager?
The email message contained a virus, and your virus disposition is set to User
Quarantine. Because virus scanning takes precedence over other filters,
messages with viruses are disposed of according to your virus disposition.
Why are large attachments being bounced, even when Attachment Manager is
turned off?
The Message Size filter is always in effect, even if Attachment Manager is off.
What happens if a message has more than one attachment, but only one
triggers an attachment filter?
If only one attachment triggers a filter, Attachment Manager performs the
disposition of that filter on the entire message, including all other attachments.
What happens if a each attachment triggers a conflicting disposition?
If two or more attachments in the same message trigger a separate filter with
different dispositions (except Ignore), Attachment Manager places the message in
the designated quarantine for the Quarantine Redirect disposition. That way, the
administrator can review the message and decide what to do with it.