---
title: Mailbox quota alerts for IMAP and POP3 monitors
description: A full mailbox doesn't warn you: new mail just bounces, and the senders find out first. IMAP monitors now read the server's quota and show how full the…
canonical: https://watchfor.io/changelog/2026-10-05-mailbox-quota-alerts
---

[All updates](/changelog#2026-10-05-mailbox-quota-alerts) ✨ New Oct 5, 2026 · v 9.5.6

# Mailbox quota alerts for IMAP and POP3 monitors

A full mailbox doesn't warn you: new mail just bounces, and the senders find out first. IMAP monitors now read the server's quota and show how full the mailbox is (for example 37.2 MB of 100 MB) at the top of the monitor page. Mailbox Almost Full warns at 90 % and turns critical at 99 %, on by default for new monitors with a login. Servers without a quota, and POP3, get Mailbox Size: an alert above a size you set in MB.

## How it works

- IMAP: after the login, the check asks the server for the mailbox's quota (the IMAP QUOTA extension, supported by Dovecot, Cyrus and most hosting providers). It only reads; nothing in the mailbox changes. Storage and message-count limits both count, whichever is closer to full.

- Mailbox space card: right after Uptime and Incidents, a thin bar that stays grey until the mailbox is close to full: amber from 90 %, red from 99 %. An unlimited quota says Unlimited ; a server without a quota shows the mailbox size when it reports one.

- Alerts: Mailbox Almost Full (90 %, warning) and Mailbox Full (99 %, critical) are one card in the Alerting tab with both levels adjustable. They are on by default for IMAP monitors you create with a login; existing monitors are unchanged, so switch it on there. A server that reports no quota never triggers it.

- POP3: the protocol has no quota command, so the Mailbox size card shows the size and message count, and Mailbox Size alerts when the mailbox passes the limit you enter in MB.

- Gmail doesn't report a quota over IMAP, and Microsoft 365 still needs OAuth sign-in, which isn't supported yet.

Details: [IMAP monitors](/docs/monitors/imap#mailbox-quota) and [POP3 monitors](/docs/monitors/pop3#mailbox-size-and-quota).

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Canonical page: https://watchfor.io/changelog/2026-10-05-mailbox-quota-alerts · Site guide: https://watchfor.io/llms.txt