I don't think that regular email protocols allow the selective downloading of messages by their age. If you want to keep stuff on the server and not see it in the mail client, the usual advice is to place it in folders that you then deselect (i.e. , unsubscribe) in the mail client.

Note that when you unsubscribe a folder, there is no automatic clean up of pre-existing material. I think this is why your messages continue to accumulate; there is no mechanism to deal with the removal of older messages.

Having said that, I've noticed that email clients on tablets and the like seem to be quite adept at managing what is stored locally, and don't seem to suffer from this issue of accumulating aged messages. I don't know what tricks they use to achieve this.

Zenos said

I don't think that regular email protocols allow the selective downloading of messages by their age.

It is possible to download only latest messages by their age (see picture). TB will download headlines of all messages but bodies and attachment only from newest emails.

The problem is that those already downloaded messages stays on disk even after selected period of time. Im looking for a way to turncate local copies of those older messages (but live headlines, so if necessary whole email can be re-downloaded from server).

Shouldn't that be possible just by removing old parts of local mbox files in TB folder?

the options you selected means:

To synchronise and keep a copy in the Thunderbird profile folder. To only download copy to profile; the most recent 60 days.

It does not mean completey wipe everything previously downloaded and then redownload only 60 days.

The result of this means it keeps downloading and synching specified emails and this will accrue over time if you keep those emails in that folder and choose to keep the original folder subscribed and synchronised.

This is really useful if you had loads of older mail in that folder on the server and did not want to start synchronising and downloading everything in the past, but only more recent emails.

Zenos proposed solution to move mails to folders you then unsubscribe from seeing is a good solution.

I've done some testing. Unsubscribing a folder causes deletion of local mbox file, subscribing it again recreates mbox file but only downloading most recent emails - this is what I was looking for.

Unfortunately this workaround can't be applied to INBOX - unsubscribing this folder does not hide it from TB and is not deleting local mbox file but it's not automatic - every other folder in every account have to be unsubscribed and resubscribed manually).

Anyway thank you, it's still less painful than reinstalling whole TB every Christmas ;)

Manually deleting local mbox files causes problems - they are not being recreated until you unsubscribe and resubscribe that folder.

What do you seek to accomplish by "reinstalling whole TB"?

To purge TB and tons of old emails from local disk, and redownload only recent messages after reinstalling TB. After year of using TB that usually gave few GB of local free space (and keep older messages on server).

But as I told, workaround of the problem has been found and we may close this tread. Unless some one wishes to make some add-on to make it more automatic.

Thank you.

Well, your messages are stored in your profile, and uninstalling and reinstalling Thunderbird just refreshes the executable; it doesn't affect the amount of disk space given over to storing messages. To purge old messages, you need to delete old messages, and that suggests to me deleting old profiles (or more specifically, the mailstores within those profiles.). And if you want to leave old messages on the server and not have them using local space, you need to put them where Thunderbird can't "see" them, which is why we suggested un-subscribed folders.

You have a machine with only SSD and no conventional HDD?

Most of us with an SSD would move the profile to HDD, and save the SSD from all the re-writing that email needs.

Zenos said

You have a machine with only SSD and no conventional HDD?

Yes, from 5 years.

I just thought it was something wrong with configuration or TB itself, because I've never run out of free space on smartphone which is handling the same email accounts and have even smaller sdcard (mostly filled with music :) ).