In every batch of virus-scanning, limit the maximum
a) number of unscanned messages to deliver
b) number of potentially infected messages to unpack and scan
c) total size of unscanned messages to deliver
d) total size of potentially infected messages to unpack and scan
Expand TNEF
Expand TNEF attachments using an external program (or a Perl module)?
This should be "yes" unless the scanner you are using (Sophos, McAfee) has the facility built-in. However, if you set it to "no", then the filenames within the TNEF attachment will not be checked against the filename rules.
Deliver Unparsable TNEF
Some versions of Microsoft Outlook generate unparsable Rich Text format attachments. Do we want to deliver these bad attachments anyway?
Setting this to yes introduces the slight risk of a virus getting through, but if you have a lot of troubled Outlook users you might need to do this.
We are working on a replacement for the TNEF decoder.
This can also be the filename of a ruleset.
TNEF Expander
Where the MS-TNEF expander is installed.
This is EITHER the full command (including maxsize option) that runs the external TNEF expander binary, OR the keyword "internal" which will make MailScanner use the Perl module that does the same job. They are both provided as I am unsure which one is faster and which one is capable of expanding more file formats (there are plenty!).
The --maxsize option limits the maximum size that any expanded attachment may be. It helps protect against Denial Of Service attacks in TNEF files.
TNEF Expander = internal
This can also be the filename of a ruleset.
TNEF Timeout
The maximum length of time the TNEF Expander is allowed to run for 1 message. (in seconds)