Trying to create a rule to delete emails on server that are older then 360 days.

POP accounts do not access the server, only the downloaded messages. Are these your concern, or the ones on the server?

I know it doesn't sync like Imap setups due.

But pop accounts has the following option (image attached) to delete on pop servers but isn't working for me.

What I think may be the issue is I am confusing Thunderbird. It would delete the email IF the email existed on the local server. Since it has already been deleted in the local drive it has nothing to initially find and compare to delete on the server.

BTW...I can't use the retention policy because according to what I read online it ALSO deletes the emails on the local server.

I am not sure I am following. Just to clarify, there is the server and there is the PC. There is no 'local' server. That is where I am getting confused. Thanks. :)

So yes...

To Keep it simple....lets just apply the goal to a gmail account.

I would like to somehow automate the ability to delete emails on the host servers as soon as they are year old.

BTW thank you for the help

My understanding is that POP has access to the server only while downloading the new mail. You cannot access messages from a prior period. Here is an example of using the 'remove from POP server' that shows its use: https://support.mozilla.org/en-US/questions/1225215 In that example, the user has set to retain messages on server for 14 days, but wants to immediately delete junk messages. That filter option achieves that. To achieve what you want, you could set up a second account in IMAP and see if you can achieve your goal that way.