The names/email addresses int he "to" and "from" headers are not the "real" recipient's and sender's email addresses - they are just text content that is inserted into the email's headers. They can match or mismatch the actual to/from addresses that mail servers act upon, depending on how the sender formats the email. When using the blacklist/whitelist filters to check addresses and domains, SpamFilter will only look at the real sender and recipient's addresses as specified in the MAIL FROM and RCPT TO smtp command. SpamFilter does not check the email addresses contained in the headers, as they can be easily faked.

This said, you can use the keyword filter to perform keyword searches against those headers, and thus look for the name in the "To:" header.

By default SpamFilter will not scan the headers for keywords, but you can use the following setting in the SpamFilter.ini file to change this behavior: