That is a user preference issue. I agree that some problems surface from misuse, but many POP users like it.

David, I don't understand your response. If the "Leave Messages on Server" option doesn't do anything for POP accounts, why would any POP users like it? I sure don't. Please clarify:

1. Does it actually do something for POP accounts? If so, please explain. For example, if checking the main option "Leave Messages on Server" prevents the messages from being deleted from the server when downloaded, that's good. But if neither of the sub options:

Until I delete them For at most X days Does anything they should be excluded for POP accounts.

I didn't say it doesn't do anything; I only acknowledged that problems can occur with misuse. The functions described do work.

David, as I indicated in my original post, there are other questions on this forum that state that at least the "Older than xxx days" option does not work for POP accounts. Here is a link to one of those other questions:

https://support.mozilla.org/en-US/questions/1446045

Within that question is the following text: Begin quote: If you never want any messages deleted off the server then in 'Server Settings':

    select 'Leave messages on server'

Note: when you compact the pop eg: Inbox' to remove all old traces of deleted and moved emails, then the emails older than 1000 days should get removed off server.

But this 'older than 1000 days' has no effect on the Pop account because it does not synchronise with server - only imap accounts synchronise with server. Meaning, unless you have deleted them from the pop account then they will still be visible in the pop account. End quote

So either you or the other contributor are mistaken. I need a definitive answer to that contradiction and to my question about the lack of any warning/explanation involving those options. Until then, "dumb users" like me cannot be accused of misusing the options.

I am fully aware of that thread. On your response, look at the 2nd and 3rd paragraphs from bottom. One states removal when compacted, and the other states that it does not synchronize. Those are not contradictions. POP requires the compacting to initiate that preference.

Here is what I am going to do: I am going to manually initiate a compacting of my Thunderbird Inbox. Once that completes, will any messages that have been deleted from the inbox since the last time the inbox was compacted be immediately deleted from the server? Or will I have to do another download to make them be deleted? I am trying to learn how this works but I need a definitive answer to these questions. I will report the results once the compacting completes and after I download more messages, but I'd really appreciate your answer before I actually complete these actions. I have no idea how long it takes to compact my inbox because I can't remember ever doing it before, because I didn't think I needed to do it.

Here are the results of my compacting exercise. Prior to beginning the compacting of my Thunderbird inbox, that inbox had 204,752 total emails. My Pop server had 72027 unread emails (That's just the way the web server works. It doesn't give me a total number of emails) Prior to starting the compacting, I had deleted 3 emails from my Thunderbird inbox, because I didn't know if emails deleted since the previous compacting (like I said, I have no idea when that was) would get deleted from the server. The compacting took at least 30 minutes. When it was finished the totals for the Thunderbird inbox did not change. The number of unread emails on the server increased by 15 to 72042 due to emails received in the 30 minute compacting timeframe. The 3 server emails that I had deleted from Thunderbird were still on the server. Next, I had Thunderbird download new messages from the server. It downloaded 38 new emails because the previous download was from a little earlier in the day. After the download completed the number of emails in the Thunderbird inbox was 214790 (up 38 from before the download). The number of emails on the server stayed at 72042. The 3 emails I had deleted from Thunderbird were still on the server; i.e. they did not get deleted. Shouldn't they have been deleted? According to what you and the other guy said, they should have been.

I've used the "Leave Messages on Server" option when I've setup Thunderbird on a different PC (laptop) so that I can check email; however, I don't want them to be deleted from the server so that I can get them on my main PC when I check there. On my main PC I do have this option unchecked so they do get deleted from the server then.

I always figured that was one of the reasons for that option. Not sure I have tried the delete messages on server after X amount of days option.

Thanks for responding but you really didn't tell me anything that I don't already know. The other "experts" who have offered their opinions and advice have been proven either wrong or rewording their answers or splitting hairs. I'm growing tired of playing word games. I guess I'll probably just have to experiment and try to figure out how to best make Thunderbird work for me. You see, I need to keep at least a few months worth of messages on the server so that I can access them from my Iphone Mail app when I am not at either of my computers. So your method of having Thunderbird delete the emails after they have been downloaded to both your PC's is no good to me. I'm not sure if the other guys understand that, even though I have explained it every way I know how.

I stand by my earlier responses. If you manage to show a bug, I encourage you to file it at bugzilla. What puzzles me is that you state you delete messages from within Thunderbird yet they remain on the server. I have not seen anyone posting that issue.

David, just to minimize any chance of misunderstanding, as I indicated a couple of posts ago, here is the sequence I followed when I did my test:

1. Deleted 3 emails from my Thunderbird inbox.
2. Compacted my Thunderbird inbox.
3. Downloaded new emails from the server.
4. After I did all of this, the 3 emails that I had deleted from Thunderbird were still on the server.

Now, did I do this properly? If not,please point out where I went wrong. If I followed protocol, is this a bug? If so, ow do I report it? What evidence do I need to provide?

You can file the bug at bugzilla.mozilla.org. Be sure to include details on whatever your settings were for the account to ensure people reading the bug report understand your settings, that it was keep until I delete. Include the steps as you showed here.

Here's an update: I went back and gave this process one more try. I was able to get both things working: After deleting some emails from Thunderbird, I downloaded the newest emails and the deleted emails were also deleted from the POP server. Then I retried using the "For at most xxx days" option. This time it worked. The only explanation I can make is that I must have been doing something wrong with the compacting process. Either I had not submitted the compact request correctly or it did not complete properly. This time I was very careful and made sure that I saw the status bar indicating that the inbox was being compacted and I waited until the "compact complete" message was issued. The failed compact attempts were almost certainly due to my unfamiliarity with the compact process. This has been a frustrating process and I have been gruff with the folks who were trying to help me.

I have one remaining question: How frequently do I need to compact my inbox in order to make this cleanup work? I can see that it might be necessary after deleting any emails from the Thunderbird inbox, but what about the "number of days" option?

> This has been a frustrating process and I have been gruff with the folks who were trying to help me.

Everyone needs to be gentle, including those who are frustrated.

1. In the pop world, compact does nothing to messages on the server. Nor does compact have anything to do with settings that involve how long messages stay on a server.

2. I highly doubt there is any reportable bug here that isn't already in bugzilla.

Wayne: Maybe I misunderstood your comment above about compacting. If you look back over this question, you will see where at least one person stated that the Leave on Server options (Until I delete them) and (For at most xxx days) are dependent on the Thunderbird folder having been compacted. Part of the frustration on this question is that even after I had tried to follow their instructions about compacting the Thunderbird folder (inbox in my case), it wasn't working. Then on 5/5, I posted that I must not have been doing the compact properly, because when I did it correctly, emails that I deleted from Thunderbird were deleted from the POP server, and mails older than the number of days specified were also deleted from the server. I don't know what else to say about your comment. I was actually hoping that one of the guys who had helped me before would answer my followup question as to how often I need to compact the Thunderbird folders to keep the deletions ontinue to work.