Suchi,

If you are receiving problems with emails containing PDF files, there’s actually two different filters that could be affecting this. They can be disabled by editing the SpamFilter.ini file.

You can disable the option to scan within PDF files for spam image signatures by setting the following value to zero:

;Specify the max number of pages a PDF document must contain in order to be scanned for spam signatures. The scan will be skipped altogether if there are more than this number of pages
SpamPDFMaxPagesToScan=0

Blank emails that contain PDF attachments only can be allowed to pass by removing the “*.pdf” value from the line below. Please ***do not remove the entire line***, just remove the vales after the “=” sign.

;SpamFilter can block emails that contain only an empty, blank body and one of the following attachment. Clear the list if you don't want to stop such emails. Specify multiple attachments separated by commas
BlockBlankEmailsWithAttachments=

In both cases the changes can be made while SpamFilter is running, without needing to restart the program.