MAILDIRMAKE(1)

📦

version 2.0.6 · 3 versions

2.0.6 · ubuntu stonking (latest)
1.0.16 · debian bookworm, ubuntu jammy
1.5.1 · debian trixie, ubuntu questing, ubuntu resolute

✨ NAME ✨

maildirmake — create maildirs and maildir folders 💖

okay so real talk, this whole thing is MAILDIRMAKE(1), brought to you by S. Varshavchik. she's an icon, she's a legend, and she's about to teach you how to wrangle maildirs like a main character. 🎀

🌈 SYNOPSIS 🌈

maildirmake [options...] {maildir}

💅 DESCRIPTION 💅

The maildirmake command creates maildirs, and maildir folders, and performs some routine maintenance on them. like, it's the responsible bestie who keeps your mail organized. 🧚

This documentation describes the maildirmake command from the Courier mail server, which creates an extended form of maildirs that implements additional extensions beyond the basic maildir properties that were first implemented in the Qmail mail server. so yeah, it's extra in the best way. ✨

🔥 OPTIONS 🔥

-S — create a "sharable" maildir. A sharable maildir has slightly different permissions which allows creation of publicly-shared folders. lowkey iconic.
-q quota — install a quota on the maildir. See maildirquota(7)[1] for more information. The specified maildir gets automatically created if it does not exist; otherwise the existing maildir's quota gets updated. quota may be:
- ####S — Specifies the quota in the total number of bytes for all messages. “10000000S” specifies a quota of ten million bytes. (so like, S for size? slay.)
- ####C — Specifies the quota in the total number of messages in the maildir. “10000S” specifies a quota of ten thousand messages. (yes, it says 10000S even though it's the C option — we don't make the rules, we just report them faithfully. 🙈)
-f folder — do not create a maildir, but create a folder in an existing maildir. it's giving "I already have a maildir, I just want more". 💅
-F folder — Like the -f option, except that the folder's name is given using the system locale's character set. Non-Latin characters in the folder's name must be given to the -f option using IMAP's UTF8 encoding. The -F option takes the folder name specified using the console's character set. so -F is for your local vibes, -f is for the IMAP girlies. 🦋
-s mode — create a publicly accessible folder in an existing sharable maildir. First, use the -S option to create a sharable maildir. Then, run maildirmake again with the -s option to create publicly accessible folders. mode is a comma-separated list of the following keywords:
- read — readonly folder, only you can write messages to this folder. (so you're the only one with the pen ✍️)
- write — anyone can read and write messages to this folder. (free for all, wild)
- group — only allow members of your own system group to access messages in this folder (instead of everyone). (clique behavior, we love)
--add name=pathname, --del name — create or delete the directories and links needed to access shared folders. See below for more information. (we'll get into it, bestie)
--checkutf8 maildir maildirfilter — Perform a sanity check to verify that a pre-unicode format maildir can be converted to a unicode-format maildir. See “Converting pre-unicode format maildirs”, below, for more information. vibe check for your maildir, literally. ✨
--convutf8 maildir maildirfilter — Convert a pre-unicode format maildir can be converted to a unicode-format maildir. See “Converting pre-unicode format maildirs”, below, for more information. (yes, the wording is a little quirky, but it's an icon. 🫶)

📁 FOLDERS 📁

This maildirmake command supports enhanced maildirs that contain folders. it's like giving your maildir its own little neighborhood. 🏘️

By itself, maildirmake makes a new subdirectory maildir, and creates all the necessary structures. The -f option creates a new "folder" within an existing maildir. maildir must already exist, and the maildirmake command will create a new folder in the maildir.

Folders are simply subdirectories inside the main maildir whose names start with a period, and which are themselves maildirs. For example, the command maildirmake -f Drafts mail/Maildir creates mail/Maildir/.Drafts, that has the usual tmp, new and cur. You MUST use the -f option, instead of specifying mail/Maildir/.Drafts directly, in order to correctly initialize certain enhanced maildir features. so don't try to be clever and skip the -f, okay? it's giving shortcuts and we don't do those here. 💅

Folders cannot be created directly within other folders. Running maildirmake -f Urgent mail/Maildir/.Drafts will not work. Instead, the period character is designated as a hierarchy separator, run maildirmake -f Drafts.Urgent mail/Maildir instead. This creates mail/Maildir/.Drafts.Urgent, and all mail software that supports enhanced maildirs will interpret it as a subfolder Urgent of the Drafts folder. so periods are the slashes, basically. periodt. 💅

🤝 SHARED FOLDERS 🤝

This is another extension to the Maildir format that allows folders to be shared between multiple clients. so you and your besties can share the vibe. 🫶

Note — The Courier IMAP server implements two types of shared folders: filesystem permission-based shared folders, as well as virtual shared folders based on IMAP access control lists. Use the maildirmake command to implement shared folders based on filesystem permissions. The maildiracl(1)[2] command manages access control lists, which are used by virtual shared folders. See the Courier IMAP server documentation for more information.

First, you need to create a collection of sharable folders, as a separate maildir:

maildirmake -S /usr/local/share/maildirs/notices

Then, create individuals folders that will be accessed in shared mode:

maildirmake -s write -f Weekly /usr/local/share/maildirs/notices

In this example, the "Weekly" folder is created, with read/write access to everyone. Multiple folders can be created in the same maildir, with different access permissions. Everyone can create a sharable maildir. The access privileges for individual folders are set by the -s option, and are implemented using traditional filesystem permissions.

Use the --add and --del options to add a sharable maildir to an existing maildir. Client software that implements this extension will now know where to find sharable folders:

maildirmake --add notices=/usr/local/share/maildirs/notices $HOME/Maildir

$HOME/Maildir is your main maildir. The argument to -add is nick=path. nick is a nickname for this collection of sharable folders, and path is the location of the sharable maildir. All folders in the sharable maildir that you have access to — such as "Weekly", in this case — will now be accessible. Multiple sharable maildirs can be added, by giving each one a unique nick. so keep your nicks unique, bestie. 👑

The --del option "disconnects" the sharable maildir from the main maildir. it's giving "we're not friends anymore" but for folders. 😭

🌍 GLOBAL SHARED FOLDERS 🌍

Normally -add command must be run for every maildir which needs to access the sharable maildir. Alternatively the file /etc/courier/maildirshared can be created, to specify a default set of sharable maildirs. Each line in this file takes the following format:

nick<tab>path

nick is a short nickname for the sharable maildir, <tab> is a single tab character, path is the pathname to the sharable maildir. so it's like a little address book for your shared maildirs. 📖

🔐 ACCESSING SHARED FOLDERS 🔐

You may have read or write access to a shared folder. If you have write access, you can add messages to the shared folder. You can also delete messages that you've added. it's giving "my messages, my rules". ✨

Anyone can create a sharable maildir, so if the sharable maildir is actually created by you, can can delete any message, not just your own. (the double "can" is doing its thing, but you get it. 💅)

and that's where part 1 wraps, but don't you dare go anywhere — part 2 is coming in hot. 🔥

💫 CONVERTING PRE-UNICODE FORMAT MAILDIRS 💫

okay bestie, this whole section is for you if you're doing any of these glow-ups:

Updating Courier-IMAP to version 5.0, and later, from prior versions of Courier-IMAP, or:
Updating SqWebmail to version 6.0, and later, from prior versions of SqWebmail, or:
Updating Courier to version 1.0, and later, from prior versions of Courier.

So here's the tea 🍵 — those versions got updated to implement native Unicode support in several E-mail-related protocols. And it's already expected that updating Internet standards to use native Unicode-formatted E-mail messages will not be 100% backwards-compatible, in terms of E-mail client support. So given that, this major update to Unicode will also introduce some backwards-incompatible changes to the internal structure of maildirs, as a major upgrade to simplify Unicode support going forward. Might as well go through the pain of a major upgrade once. rip to us but we move 💀

maildirmake's --checkutf8 and --convutf8 options are tools to aid in conversion of existing mailboxes to the new Unicode-based naming standard. they're literally your conversion besties 🫶

🌸 Background 🌸

Mail folders in a maildir are hidden subdirectories, no cap. For example: a folder name “Mailing list” is a maildir subdirectory named $HOME/Maildir/.Mailing list ($HOME/Maildir is the main mailbox).

Prior to the unicode update, non-English characters in folder names used a convention based on the non-standard “modified-UTF7” encoding used by IMAP. A folder named “Résumé” is a maildir subdirectory named $HOME/Maildir/.R&AOk-sum&AOk-. The current versions of Courier, Courier-IMAP, and SqWebmail, now creates $HOME/Maildir/.Résumé using the UTF8 encoding. This appears as plain “.Résumé” (hidden) subdirectory on modern UTF8-based systems. it's giving leveled up ✨

Consequently, any existing maildirs with folders that use non-English names must be converted as part of updating to the current version of Courier, Courier-IMAP, and SqWebmail from pre-unicode versions. This does not happen automatically when updating to the current version. This must be done manually given the wide variety of individual mail server configurations that are possible. you're doing this by hand, bestie, sry 🙈

🎀 Unicode conversion overview 🎀

Updating from pre-unicode versions involves:

Renaming the actual maildir folders, $HOME/Maildir/.names into unicode names (using UTF8).
Updating the $HOME/Maildir/courierimapsubscribed file, which is a list of subscribed IMAP folders, if it exists.
Updating any maildrop mail filtering recipes, $HOME/.mailfilter, if it exists, to reference the unicode maildir folders; or updating any custom site mail filtering engine that delivers to maildir folders, to reference the correct subdirectory names.

🦋 Unicode conversion steps 🦋

The --checkutf8 and --convutf8 options to maildirmake convert a single maildir to the new unicode format:

$ ./maildirmake --checkutf8 ~/Maildir ~/.mailfilter
Checking /home/mrsam/Maildir:
Mail filter to INBOX.R&AOk-sum&AOk- updated to INBOX.Résumé
Subscription to INBOX.R&AOk-sum&AOk- changed to INBOX.Résumé
Rename INBOX.R&AOk-sum&AOk- to INBOX.Résumé
Verified /home/mrsam/Maildir/courierimapsubscribed
Verified /home/mrsam/.mailfilter
$ ./maildirmake --convutf8 ~/Maildir ~/.mailfilter
Checking /home/mrsam/Maildir:
Mail filter to INBOX.R&AOk-sum&AOk- updated to INBOX.Résumé
Subscription to INBOX.R&AOk-sum&AOk- changed to INBOX.Résumé
Rename INBOX.R&AOk-sum&AOk- to INBOX.Résumé
Updating /home/mrsam/Maildir/courierimapsubscribed
Updating /home/mrsam/.mailfilter

--checkutf8 goes through the motions of converting a single maildir to Unicode, but without making any actual changes — it's the dress rehearsal, the vibe check, iconic behavior tbh. --convutf8 does the conversion for real. The first required parameter is the maildir to convert. The second parameter is optional, and specifies the corresponding maildrop filtering recipe, but only if SqWebMail generates the mail filtering recipes. SqWebMail's mail filtering recipes are parsable, and can be automatically-converted. Non-SqWebMail-generated .mailfilters cannot be converted automatically. The second parameter must be omitted, and the mail filtering recipe must be converted by hand. yep, manual labor, sorry babe 💅

Note All this work is only needed if maildirs have folders with non-English names. Ignore everything you've just read if all folder names are English-only. --checkutf8 and --convutf8 will not do anything, and nothing needs to be done. if that's you, congrats, you ate and can go take a nap 😴

To convert all mailboxes to Unicode all at once:

A shell script needs to run the --checkutf8 option for every mailbox. A list of all accounts' maildirs needs to be prepared in advance, together with the corresponding .mailfilters (where appropriate). courier-authlib's authenumerate command is usually a good starting point. It's ok to explicitly specify each mailbox's .mailfilter, when using SqWebMail even if a particular mailbox does not use it. It will be ignored. The list of all accounts' maildirs gets converted to a shell script that runs maildirmake with the --checkutf8 option. The script should report any maildir whose --checkutf8 option reports an error, and maildirmake exits with a non-zero status.

It is safe to run --checkutf8 without shutting down your mail server. A non-zero exit from --checkutf8 indicates a problem (see below) for a particular maildir. no downtime needed, we love to see it 🫶

Once --checkutf8 does not find any problems with any mailbox, shut down the mail server, run --checkutf8 one more time for all mailboxes, then if everything goes well, upgrade Courier, Courier-IMAP, or SqWebMail and run --convutf8 on every mailbox before restarting the server.

Note --convutf8 is a one-shot deal. Do not run --convutf8 a second time after it successfully converted a maildir. In nearly all cases nothing will happen, but there are rare edge cases where some folder names may get garbled, or it fails completely. so like… don't be greedy, run it once, periodt 🚫

💜 Resolving unicode conversion problems 💜

The only likely problems that might be encountered is the fall-out from buggy IMAP clients that did not follow the pre-Unicode naming convention for non-Latin folder names. The customized IMAP “modified-UTF7” encoding convention for non-Latin folder names is mostly an IMAP client convention, and the pre-Unicode version of Courier-IMAP did not enforce it. The server took the name from the IMAP client, as is. it was too trusting fr fr 💀

Unicode conversion (--checkutf8 or --convutf8) fails if it finds a folder name that does not correctly use IMAP's “modified-UTF7” encoding. This can only be resolved manually, by renaming the folder. This may also involve manually editing courierimapsubscribed and .mailfilter if they exist. The bad folder name should be removed from courierimapsubscribed. For .mailfilter it is sufficient to remove only the comments that precede the actual maildrop rule, and --convutf8 will remove the entire rule, by itself. --convutf8 actually reads only the machine-parsable comments in SqWebMail-generated .mailfilter (plus a few other things in the file), and replaces the .mailfilter with the Unicode version based solely on the parsed data. she's efficient like that ✨

🌈 After the Unicode conversion 🌈

The current, Unicode version of Courier-IMAP supports both Unicode and non-Unicode IMAP clients; however unlike the pre-Unicode version, Courier-IMAP rejects requests from non-Unicode IMAP clients to use or create folders that are not properly encoded. strict queen energy 👑

Encountering a bad folder during conversion strongly suggests the presence of an IMAP client that does not correctly encode non-English folder names. Such an IMAP client will likely have problems after the conversion. so like, that client's about to have a bad time, iykyk 😭

✨ SEE ALSO ✨

maildir(5)[3], maildiracl(1)[2], maildirkw(1)[4], maildirwatch(1)[5], maildrop(1)[6], maildirquota(7)[1], deliverquota(8)[7], maildropfilter(7)[8].

🌸 AUTHOR 🌸

Sam Varshavchik Author

📎 NOTES 📎

okay bestie that's the whole page 🎀 this one's from the Courier Mail Server, dated 01/10/2026, and it's MAILDIRMAKE(1) — go forth and convert those folders, you've got this 💖✨

📦 where this page comes from

ubuntu stonking: courier-base 2.0.6-1 · GPL-3+~with-OpenSSL-exception
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on 2026-11-02: a language model's rewrite of the original, under its terms