Do you also have until I delete them checked?

Matt said

Do you also have until I delete them checked?

No, should I ?

Pop mail account I check both "Leave message on server" and " for at most 1 days".

Pop mail accounts usually by default allow you to download and then they auto delete off the server.

Selecting 'Leave message on server' would prevent the auto deleting off the server. Selecting 'For at most 1 day' should delete anything older than one day. Selecting 'Until I delete them' would leave all messages on server except for those you delete.

Or if you had selected 14 days to leave on server AND until I delete them, then anything you delete should be removed upon deletion and delete anyway if older than 14 days.

Mind you, I have some emails that are auto filtered into 'Deleted' folder and noticed they do not get deleted off the server, so I had to include a filter option to delete from pop server.

Deleting is not enough, you do have to select 'Empty Deleted' and when Thunderbird makes next 'Check for messages' it then deletes off server.

I notice you have selected for emails to stay on the server and then stay for only a day. What is the reason for selecting to keep them on server if you want them deleted almost immediately?

You could uncheck the option 'leave messages on server.'

Ok, I think I get it, finally. The above solution is correct: Check "Leave Messages on Server" and check "For at most so many days." Also, it appears, that if one has multiple emails, like me, one needs to do the above checking on the "main" email server setting. On my previous experiment I set the Server Settings on one of the "subordinate" email accounts, and that seemed to do nothing, but when just an hour or so ago set the parameters for the "main" account, then the emails were downloaded to Thunderbird, they were deleted from the server.

Also, in answer to the question "why did I set the retention period to only one day ?", that was because I didn't want to wait 15 days or so to see the results of my experiments. Now that the experiments are over I have reset the retention period to 15 days; this serves as a nice backup of recent emails, should my computer die.

Thanks for the help.

Totally agree with you on settings. I have pop mail accounts and leave on server for a month. I also do a backup once a month, so between the two, I should not lose too much in the event of loss. good to hear all is now working as expected.