During the regular usage of PureMessage for Microsoft Exchange 3.0.2, the scanner service hangs with errors like this appearing in the SMTPScan.log:
Failed to call content engine scan method while processing message (error: '0x8007000E')
Sophos product and version
PureMessage for Microsoft Exchange, version 3.0.2
Windows 2000, 2003 and 2008
An invalid regular expression causes PureMessage to hang
What to do
There was a bug in PureMessage for Exchange 3.0.2 whereby the scanner service would run out of memory if either the Blocked Phrases list or the Offensive Words list contained invalid regular expressions (otherwise known as "regex", a language allowing for text pattern searches -- examples of valid ones can be seen in this Support article on how to handle NDR spam).
Customers are encouraged to upgrade to the latest version of PureMessage which addresses this issue.
For those customers unable to upgrade and encounter this error, isolating which rule within the content-based policy rules would be the best course of action. Through the PureMessage console, look through the Blocked Phrases and Offensive Words lists for any custom-added entries and try disabling them temporarily to see if the problem goes away. The use of multiple wildcards within one regex will add substantial time and overhead for scanning. Otherwise, disabling Attachment searches for regex searches will also help, particularly if large attachments are normally being scanned.
If required, the default policy that comes bundled with PureMessage could be used a reference to restore the original lists.
Please note that Sophos can only provided limited support for custom regex recipes.