Exim - sorting emails by dates?

Question

linux

Greetings.
The situation is this:
Exim is used, there is a box on the server that receives a lot of letters. As a result, there are so many files (tens of thousands) in the maildir directory for this mailbox that when they are listed (through the imap server, for example), everything starts to slow down very much, resting on the file system).
The only optimization idea at the moment is to add a rule to decompose these letters into directories by dates using sieve. But for now I'm not sure if it's feasible.
Perhaps you can offer some other ideas? Has anyone encountered such difficulties?

Answer 1

1. Look towards mbox.
2. To look towards regular taking away by the client of mail on any pop3 thread.
3. Look towards the removal of mail somewhere towards clouds like gmail/mailru/yandex/office365
Already among several of my familiar companies after test deployments of exim/postfix/sendmail/exchange on such volumes of mail (from 10 gigabytes per user on average) - companies from a dozen users to half a thousand, it was decided that it was more economical and profitable to refuse local mail servers in service.
because the business needed to have the availability of the mail archive not in the local archive on the client, but the ability to be accessed at any time - frequent business trips

Answer 2

For such operations, there is sieve. You need to connect it to a software that sends letters via imap (most likely dovecot) and for each user you can write your own script for unpacking letters. Moreover, the script can be created directly from the mail client. Thunderbird and claws-mail can do this, for example.