What is the problem with having huge online mailboxes? Just choose a good european provider that has encryption all the way through to their storage platform.
I had exactly the same idea about migrating. You have to think twice about moving emails around of users. They do not like it ;) I have created an 'archive' environment on a distributed filesystem, and it takes me quite a lot of persuading to have people (or allow me) to move messages from common Sent and Inbox mailboxes to the Archive namespace (was not able to use the alternative storage option that dbox allows). Side note is that if you do archive these emails, most users do not even notice you have done this.
I ended up creating a script and a webmail plugin for users to enable autoarchiving, which creates something like this.
[@~]# mailbox-ls.sh testtest size listing mailboxes of testtest: Archive messages=0 Archive/2011 messages=0 Archive/2012 messages=0 Archive/2013 messages=0 Archive/2014 messages=0 Archive/2015 messages=0 Archive/2016 messages=0 Archive/2017 messages=0 Archive/2018 messages=0 Archive/2019 messages=3500 Archive/Archive messages=1 Deleted Messages messages=16 Drafts messages=2 INBOX messages=1286 INBOX/test2 messages=11 Junk messages=2 Sent messages=0 Trash messages=132
A cron job checks then if the script has run for the user this year, if not it starts archiving in the down hours otherwise it runs again in next year's 2nd quarter. What ever you choose, move messages with "doveadm move". I would not trust anyone else's programming with my users email, you should also not. Read the man pages on tools that work via imap, if they change headers, users are going to download all their messages again. I was thinking of splitting up folders like eg inbox/sales to Archive/2016/sales, Archive/2017/sales. But when I migrate to mdbox this is not necessary anymore.
I do not like the sound of "Postfix BCC feature", I use sendmail and I can duplicate messages with that, without altering anything in them. You do not want anything that changes your data. If your provider uses this mdbox format (maybe others support this also) then messages a user deletes, are not even removed from the server until "doveadm purge" is given ;)
-----Original Message----- From: R. Diez [mailto:rdiezmail-2006@yahoo.de] Sent: Monday, October 19, 2020 3:49 PM To: dovecot@dovecot.org Subject: How to move/reorganise existing e-mails to yearly subfolders
Hi all:
I am new to e-mail servers and I am evaluating Dovecot. Not really the best combination. 8-)
I am trying to find a balance between legal data retention requirements and online mailbox size. I do not want huge online mailboxes, as doing offline, rotating data backups could then take forever (among other reasons). I would rather avoid online (cloud) backups (data protection etc.).
If I set a mailbox size limit, users will have to delete old mails by themselves. Or I could somehow script the deletion of attachments from old e-mails, as attachments are usually the main cause of huge mailboxes. Incidentally, can anyone point me to an easy way to achieve this? Preferably over with IMAP, otherwise with Dovecot tools.
With regards to legal data retention (which I am no expert about either), I thought I could use some Postfix BCC feature I heard about in order to copy all incoming and outgoing e-mails to a single "data retention" mailbox. Or maybe several of them. I could then archive e-mails from that mailbox on a yearly basis.
I would like to automatically organise e-mails inside that mailbox into subfolders like this:
2019/alice 2019/bob 2020/alice 2020/bob
That is: [year]/[username]
With such a folder structure, it is easier to see what is going on.
Is there a tool that can reorganise existing e-mails into such a folder structure?
I found some tools on the Internet to backup and export mails from IMAP to IMAP or maildir destinations. But I could not find a tool that just reorganises (moves) e-mails in such a manner inside an existing mailbox, maybe with a user-defined pattern for the destination folders.
I guess moving e-mails around on the same mailbox would be much faster than exporting and reimporting them in some clever way.
I could always write a Perl script, but that takes time. Such a tool may already exist. Or perhaps somebody could mention a similar, good-written script I can use as a starting point. I am sure there are many small gotchas to avoid. At the moment, I am only confident with Perl and Java. Maybe JavaScript.
It would be best to reorganise the e-mails over IMAP. This way, I am independent of the e-mail server. But a Dovecot-specific solution would also be helpful.
I could use such a reorganisation tool not just for archiving or data retention purposes, but to reorganise other mailboxes too, like my personal mailbox.
I would rather have a script. Clicking around in Thunderbird does not scale.
I have seen that you can use a "sieve" in Dovecot to achieve this. But I guess that would only apply to new e-mails. And that would probably apply just to incoming mails, and not to outgoing ones. If I migrate from the existing e-mail servers, the e-mails will probably be mass-imported without going through any "sieve", right?
Besides, I already have a few huge mailboxes with many years of e-mails, stored in a different e-mail server, and it would be nice to be able to reorganise them as they are. That way, I could archive the existing older e-mails before migrating to Dovecot, which would reduce the disk size and the export/import time for the migration.
Many thanks in advance, rdiez