Can I use a regex in messagesize.rules

[Ram]

I have MailScanner version 4.70.7 on  CentOS 5.2 

If I have a rule in MailScanner messagesize like 

To: ram at netcore.co.in 10000 
This works fine 



Some regular expressions  like these work too
To: ram@(mumbai\.)?netcore.co.in 10000


But Expressions like these dont work 
To: ram@(.+\.)?netcore.co.in




Are these regular expressions supported