Email filter "Begins With" bug
If you create an email filter rule with "Begins With", it does not create the rule expression with a space between the email header field and the data. For example, if you specify "Subject Begins With test", the rule becomes:
(/^Subject:test/:h)
This will not work since the header field "Subject:" always has a trailing space. You can work around this by putting in a leading space (before the word "test" in this example) to make the rule work, but I feel this is a bug.