MyPopBarrier can purge your mailboxes from undesirable messages even before they are downloaded to your local inbox. The application has quite a straightforward interface and it is not difficult to configure. You should start by setting the desired email accounts, and fortunately, it is possible to configure various mailboxes. Regrettably, however, the help documentation, which is available from the About window, is not very explicit.
An important part of discriminating good messages from bad ones is creating white and black lists. The black list, for instance, includes some words by default, which does not mean you cannot add others. Likewise, it is possible to add trusted domains to your white list to avoid false positives. Thus, once the list of messages is imported from the selected accounts, some messages are marked with a red dot, which means that they will get deleted if you click on the Purge button. Nevertheless, you can change a message status from one status to another by simply clicking on it.
Luckily, you can automate some operations. For example, it is possible to include some post-purging actions, such as starting a given application, like your email client. It is also quite convenient that the tool can be scheduled to download messages automatically at the specified frequency.
In general, MyPopCarrier works perfectly. Still, it is a shame that there is a window that gets distorted when resized. Fortunately, the product can be used for free indefinitely and the developer suggests an optional registration, which resembles a donation instead of an actual payment.