MAILDIRQUOTA(7)

💖 MAILDIRQUOTA 💖 (section 7 of the manual, bestie)

okay so this is the maildirquota page, and it's all about voluntary Maildir quotas ✨ yep, voluntary, like when you promise yourself you'll only have one snack and then… you have four. Anyway. Author vibes: S. Varshavchik. Let's get into it 🫶

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✨ SYNOPSIS ✨

maildirmake {-q} {10000000S} {./Maildir}

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🌸 DESCRIPTION 🌸

So maildrop has a manual quota enforcement implementation — the kind that does use the quota facilities of the host operating system (aka filesystem-based quotas). This is an option that gets set at configuration time, and ngl it can be disabled. 🎀

Using filesystem quotas sometimes leads to problems, and it's giving chaos energy 💀 Once a hard quota is hit, most commands issued by mail clients fail — including some commands that poorly-written mail software may not expect to fail, which means it just cannot gracefully handle that unexpected failure. embarrassing for them, honestly.

With manual quotas tho? The only operations that fail are the ones that most mail clients already expect to fail when the mailbox is full. ✨ Slay. But here's the catch: filesystem-based quotas cannot be used in some situations, like virtual mailboxes. So if this experimental feature is enabled, approximate quota enforcement can be implemented by maildrop or deliverquota to whatever extent it's possible to do so. Quotas get enabled by the -q option to maildirmake. And both maildrop and deliverquota will observe any maildirmake-requested quota. 👑

🔥 LIMITATIONS (read this part fr fr) 🔥

This quota mechanism will only work as long as maildrop (or deliverquota) are the only applications that deliver messages to the maildir — OR as long as other applications implement the same quota enforcement mechanism. The quota enforcement mechanism is described separately in the README.maildirquota.html file in the source code distribution. 📄

Quota enforcement will still work, to some extent, if there are other applications that deliver or modify messages in the maildir. However, quota enforcement may not kick in immediately when the maildir goes over quota — in fact, the maildir can go over quota by a noticeable amount. 😭 But eventually, as long as maildrop or deliverquota are responsible for delivering the majority of messages, quota enforcement will kick in. Also, other sources of messages may also result in noticeable performance degradation, because quota recalculation will become noticeably more expensive. 💀

Also keep in mind that this quota mechanism is generally useless if mail recipients have direct access to their maildirs. yeah. useless. periodt.

And finally — even under the best conditions, this quota enforcement does have a small chance of a race condition where a maildir will go over quota by some amount. 🏃♀️ maildirs are designed for speed, and this quota implementation was designed to have as little additional overhead as possible, compared to regular maildirs. To enforce an exact quota you would have to use some kind of a locking facility, which will impose a drastic performance degradation on the overall maildir performance. A decision has been made to avoid locking, with the only negative side effect being a possibility of going over quota in very low probability situations. that's the tradeoff, bestie 🤝

A way to minimize the risk of going over quota is to set reasonable quotas, in relation to maximum message sizes supported by your mail server. If you set your maildir quota to five gigabytes, for example, it makes very little sense to configure your mail server to accept messages up to three gigabytes in size. Your maildir quota should be chosen so that it makes sense when compared to the maximum message size allowed by your mail server. 🧠✨

🎀 FOLDERS 🎀

This quota implementation is compatible with a popular extension to maildir which defines individual mail folders within a single maildir. 🗂️ BUT — and this is the important part — in order to create a compatible folder, you MUST use the maildirmake command that comes with maildrop, and you MUST use the -f option to maildirmake, giving the name of the folder. Do not use maildirmake and specify the directory name of the maildir folder. Quota enforcement will not work if you do that. 🙈 no cap.

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💜 SEE ALSO 💜

• maildrop(1)[1]
• maildirmake(1)[2]
• maildropfilter(5)[3]
• deliverquota(8)[4]

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👑 AUTHOR 👑

Sam Varshavchik Author

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📎 NOTES 📎

1. maildrop(1) http://www.courier-mta.org/maildrop.html
2. maildirmake(1) http://www.courier-mta.org/maildirmake.html
3. maildropfilter(5) http://www.courier-mta.org/maildropfilter.html
4. deliverquota(8) http://www.courier-mta.org/deliverquota.html

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okay that's the whole page, you ate it up 💅 this came from the Courier Mail Server, dated 01/10/2026, and honestly? iconic. go set a reasonable quota and text me back 🌈🦋💖