How does that make sense? Sure, "Expunge" is about telling the server to "commit" the message deletions, but "Compact" should be about the client performing its commits locally only. Like, in context of local accounts configured as 'mbox', where all messages in a folder are stored in one file. The local disk space formerly occupied by deleted messages is not recovered for other use until that folder/mbox file is "Compacted". (In the early days when disk space was at a premium and compacting was worth doing, it was the source of much file corruption, too often losing or scrambling many or all of the messages in the folder. Changing the mailstore file-scheme "Message Store Type" from all-in-one to one-for-one was seen as a boon, because it was no longer useful to run the buggy and/or failure-prone compaction code.) Does Compacting even apply to local accounts configured as MailDir, where each message is stored in its own file? I never see the Compacting prompt because my messages generally are stored on the server-side only, and not copied to local. (Account Settings => Synchronization & Storage => Message Synchronizing => [ ] Keep messages for this account on this computer) No local message files exist, neither per-message MailDir files nor per-folder mbox files, therefore no compacting can be done.On a IMAP server, [before "Compaction" happens, deleted messages may silently persist] marked as "to be expunged" on the server [until] closing the client [when "Expungement" happens].
[Messages in] Trash and Junk folders [where more deletes happen] are marked as "to be expunged" but [not] expunged until the folders are compacted.
Also it seems silly to worry about non-privacy from not-yet-actually-deleted messages, considering that hosting servers take backups of all the mail all the time anyway. AND, within the past coupla years the good hosts have begun storing all mail as encrypted anyway; I assume decryption happens only via the account login, including password, before IMAP download.
