Mail filters not working consistently

Mail filters not working consistently

Greetings,

I am making use of the mail filtering facility to sort incoming mail into specific subfolders. I find that the filtering criteria sometimes work automatically, and sometimes they don't.

Sender (equals and begins with) works perfectly. Mail is automatically moved into specified subfolders.
To (equals) is ignored. These mails end up in the default input mail folder. Then, when i manually issue a Run through filters requests in the Personalize Mail/Filters settings tab the filter is applied and the mails are moved.

Is this a known issue?

Regards
Rainer Thiel