A common goal is to filter incoming messages, perhaps automatically rejecting or discarding some based upon material in the messages' headers. One way to do this is via the DELIVER facility discussed in Chapter 4 . Another alternative is to use PMDF's web-based mailbox filtering, as described in this chapter.
If your messages are delivered to the native message store (VMS MAIL mailbox) or to a PMDF popstore or PMDF MessageStore account, your system administrators may have chosen to enable another option: PMDF message filtering. If your system administrators have chosen to enable it, PMDF provides a web-based interface through which you can construct and manage your own message screening rules.
Each mailbox filter contains six distinct filters: three to identify messages to always keep, the "Keep filters"; three to identify messages to always discard, the "Discard filters". The Keep and Discard filters operate on envelope and header source addresses, header destination addresses, and phrases or words appearing in the Subject: header line. The six filters are thus known by the names Keep From, Keep To, Keep Phrases, Discard From, Discard To, and Discard Phrases.
By default, you have no mailbox filter (unless your system administrator has chosen to set one up for you). When you use the web-based interface (and if mailbox filtering has been enabled for your account), then a mailbox filter is created for you. Your mailbox filter will be stored in a file; the location of that file is site configurable, but you should not need to know where it is in any case as you cannot modify the file manually. All modifications to your filter are done using the web interface.