Processing Incoming Mail

Max Unsafe Bytes Per Scan

Limit the maximum number of unscanned messages to deliver.


Max Unsafe Bytes Per Scan

Limit the maximum number of potentially infected messages to unpack and scan.

Max Unscanned Messages Per Scan

Limit the maximum total size of unscanned messages to deliver.

Max Unsafe Messages Per Scan

Limit the maximum total size of potentially infected messages to unpack and scan

Max Normal Queue Size

If more messages are found in the queue than this, then switch to an "accelerated" mode of processing messages. This will cause it to stop scanning messages in strict date order, but in the order it finds them in the queue. If your queue is bigger than this size a lot of the time, then some messages could be greatly delayed. So treat this option as "in emergency only".

Maximum Attachments Per Message

The maximum number of attachments allowed in a message before it is considered to be an error. Some email systems, if bouncing a message between 2 addresses repeatedly, add information about each bounce as an attachment, creating a message with thousands of attachments in just a few minutes. This can slow down or even stop MailScanner as it uses all available memory to unpack these thousands of attachments. This can also be the filename of a ruleset.

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)

File Command

Where the "file" command is installed.
This is used for checking the content type of files, regardless of their filename.
To disable Filetype checking, set this value to blank.

File Timeout

The maximum length of time the "file" command is allowed to run for 1 batch of messages (in seconds)

Maximum Message Size

The maximum size of any message including the headers. If this is set to zero, then no size checking is done. This can also be the filename of a ruleset, so you can have different settings for different users. You might want to set this quite small for dialup users so their email applications don't time out downloading huge messages.