Hi. I'm looking for a way to block message removal by the server in the IMAP protocol - the "(server) append only mode" (it should be still possible to delete/move messag… (read more)
Hi. I'm looking for a way to block message removal by the server in the IMAP protocol - the "(server) append only mode" (it should be still possible to delete/move message from Thunderbird).
Why? I see 2 main use cases:
1. The (corporate) server has message retention set globally (e.g. to 1 year) which "cannot" be changed. Users might want to keep their "important" email longer (and in addition, keep it in the same folders as before, not using the folders copy in the "Local folders" space).
2. Due to the unexpected situation - a server error, fire in a data center, a ransom attack, malicious email provider - all the email (or some of them) are removed from the server. Thunder would sync with the server removing the messages from the synchronized folder on a computer (sure, backup is good, but for the "silent action" - e.g. part of the emails deleted (or encrypted), it might take too long to detect that problem and still have a valid backup).
The are some (not perfect) workarounds, including:
- keeping old emails in the "Local folders" - two places to search (or many if you have a folder hierarchy with the automatic filtering)
- a separate, local IMAP server to keep an "append only" copy of the message (e.g. isync, offiline imap), possibly to be used by Thunderbird (instead of the upstream IMAP server)
- using POP3 (with its own downsides :) )
An obvious downside of the implementation in Thunderbird - which users of that feature have to be aware - is not doing any delete/move operations on the server (e.g. with the webclient or some other IMAP client). Nevertheless, to fulfill the aforementioned requirement it doesn't seem a high cost.
1. Is it possible to achieve in Thunderbird itself?
2. Is there any API to help implement that as an extension?
3. Have you - by any chance - tried to implement that using the third party tools (e.g. a local IMAP server which is used by TB) and can recommend any solution?
4. (Bonus) Do you think it would be an useful addition to Thunderbird?