Although the spam filter does collect a lot of obvious spam, I also get a bunch of other messages that I occasionally down't need to read.

I use a preview application that shows me the header information and a portion of the message body. I can then choose to delete anything that I don't want to pass along to my regular email program.

Occasionally (and even once is too often) when the preview program rescans the mail after deleting a couple, it finds that a lot of mail that was not marked for deletion wasn't even found the next time.

The preview message log even shows that some messages that were marked for deletion were no longer available to be deleted.

A few years ago, there were no problems with this approach. And since the preview program hasn't been updated in even more years, the problem must be in what Powweb mail is returning on subsequent scans.