OT Thunderbird filters working around lack of ELSE function.

[Art Kendall]

I don't know if it is still true, but IE used to be forbidden on computers where security was an issue.  Many of us used the predecessor program NETSCAPE later called ThunderBird. 

I posted a help message on Mozilla to help me keep track of my messages.
A member was kind enough to reply

1. filters work in the order you create them.
2. Filters do not have an else
3. You can not specify an entire address book for a filter.
4. You can not call another filter from a filter

I developed this workaround.

The order of the filters can work as an implicit ELSE since each subsequent filter only works on messages that have not been moved to another folder.

1. create a stack of filters that meet conditions you can specify and that move messages to specific folders. This can be many filters that are executed in the order in the list.
2. create a filter with as many lines as necessary to move residual messages that are from senders in your address books. I call this folder "known senders". In my situation that is a filter with 4 conditions joined by OR. (I.,e, that filter is an ANY filter.
3. create a psuedo-ELSE filter by testing whether the subject in residual messages is a very improbable string like if subject isn't '~@#$%^&*()(*&^%$#@!' move it to a specific folder. I call that folder "suspicious mail"

I frequently mark messages in the "suspicious" folder as junk.
I create new filters from messages the "suspicious" or "known sender"