Validating Email addresses

Julian Field MailScanner at
Mon May 11 21:14:14 IST 2009

On 11/05/2009 21:03, Paul Lemmons wrote:
> -------- Original Message  --------
> Subject: Validating Email addresses
> From: Julian Field <MailScanner at>
> To: MailScanner discussion <mailscanner at>
> Date: 05/06/2009 01:57 AM
>> On 05/05/2009 18:55, Paul Lemmons wrote:
>>> We are getting a great deal of Spam bypassing both Postini and Mail 
>>> Scanner due to a discrepancy between how these two products define 
>>> an email address and the way Exchange does. The two scanning 
>>> products recognize emails with a pipe character "|" at the beginning 
>>> of the address as both valid and part of the email address. I 
>>> believe this is in line with the email standards. Exchange, othe the 
>>> other hand simply ignores the character. So a message sent to 
>>> me at and |me at are seen as two different addresses 
>>> by the scanning systems and as a single address by Exchange.
>> Set "Reject Messages" to point to a ruleset, and have a ruleset that 
>> looks roughly like this:
>> FromOrTo: /^\|/ yes
>> FromOrTo: default no
>> and MailScanner will reject messages coming from or going to an 
>> address starting with a pipe character.
>> Simple as that.
>> Remember to "service MailScanner reload" after changing the ruleset 
>> and MailScanner.conf file.
>> Jules
> I have tried this and now I am getting a new message in my log....
> MailScanner[5583]: Cannot match against destination IP address when 
> resolving configuration option "rejectmessage"
> # cat reject-messages.conf
> FromOrTo: /^\|/ yes
> FromOrTo: default no
> Any thoughts?
As your regexp doesn't contain any alphabetic characters, its heuristic 
code for deducing the pattern type is going wrong. If you change it to 
something like "/^\|[a-z0-9]/" then it is more likely to work.


Julian Field MEng CITP CEng
Buy the MailScanner book at
Follow me at

MailScanner customisation, or any advanced system administration help?
Contact me at Jules at Jules.FM

PGP footprint: EE81 D763 3DB0 0BFD E1DC 7222 11F6 5947 1415 B654
PGP public key:

This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.

More information about the MailScanner mailing list