[Feature Request] Quota Warning to user mailbox if user mailbox reaches 90% of allowed space

[mas1701]

Impacted versions

• OS Type: any supported
• OS Version: any supported
• Database Type: any supported
• Database version: any supported
• Modoboa: 1.17.0 or newer
• installer used: N/A
• Webserver: any supported

Steps to reproduce

Current behavior

Users using MS Outlook. Unfortunately, Outlook does not show mailbox quotas or quota warnings, except for MS Exchange mailboxes. Deliberately, I'd guess. Therefore, users IMAP mailboxes fill up to the point where no new mail can be delivered.

Recommending users to switch to another e-mail client like Thunderbird is no solution in a business environment where a lot of computers would be affected by this change. With cursing IT admins pushing for Microsoft 365 instead, despite GDPR problems.

Expected behavior

While this is not Modoboa's fault at all, I'd suggest a way to send automatic warnings to users consuming more than 80%, 90% oder 95% of their quota or having less than 50 MB / 100 MB free, whichever is reached first.

Possible solution

A warning plugin that sends quota warnings on a per-mailbox level to affected users in danger of quota overrun. Customizable text preferred.

As an intermediate solution, a quick-and-dirty hack would be acceptable.

[tonioo]

@mas1701 Have you checked https://doc.dovecot.org/configuration_manual/quota/#quota-warning-scripts ?

[mas1701]

@mas1701 Have you checked https://doc.dovecot.org/configuration_manual/quota/#quota-warning-scripts ?

Yes, @tonioo , thanks!

I already noticed this Dovecot-internal feature, but currently, I'm experiencing some trouble getting dovecot-lda to work at all. So far, dovecot-lda has yet to deliver any mail to a user's mailbox, even a simple test does not work. I'm on Debian 10 btw.

I will however check the information you provided, since there seem to be some minor differences here and there. Maybe it helps.

[mas1701]

Got quota warnings to work now, after fixing some permissions, however there is one strange message:

Sep 3 03:40:36 mailsrv dovecot: lda(E-MAIL-ADDRESS-HERE)<106566>: Error: quota: Failed to get quota resource STORAGE_BYTES for INBOX: quota-dict: dict_lookup(priv/quota/storage) failed: Connection closed (reply took 0.000 secs (0.001 in dict wait, 0.000 in other ioloops, 0.000 in locks)) - copying mail anyway

Although it says "error", not "warning", I'm still getting the correct quota warning mail.

[tonioo]

@mas1701 Don't you see anything else interesting in your logs?