Dovecot 2.4.1 on DietPi/ARM64: Cannot move/delete any folders via IMAP, and three specific folders are unreadable (but other folders work)
Hello,
I'm running Dovecot 2.4.1 on a Raspberry Pi 4 with DietPi (Debian 13, ARM64) and had to migrate from another OS with Dovecot 2.3. My maildir is at /var/mail/mailuser. It contains many dot‑prefixed subfolders, e.g. .Archiv, .Archiv.Reisen, .Sozio. Relevant parts from doveconf -n: text
dovecot_config_version = 2.4.0 auth_mechanisms = plain login dovecot_storage_version = 2.4.0 listen = * login_trusted_networks = 192.168.178.0/24 mail_driver = maildir mail_home = /var/mail/%u mail_path = /var/mail/%u protocols = imap ssl = no passdb pam { driver = pam } userdb passwd { driver = passwd } namespace inbox { inbox = yes prefix = separator = . }
Problem 1: Cannot move, delete, or rename any folder via IMAP. In Thunderbird, I can move individual messages between folders, but I cannot move, rename, or delete any folder itself. This affects all folders, not just specific ones. Right‑clicking a folder and choosing “Delete”, “Rename”, or dragging a folder to another location does nothing – no error, just no effect. I have checked permissions on the maildir; mailuser owns the directories and files, and dovecot is in the mailuser group.
Problem 2: Three specific folders cannot be opened (message body not loaded). Most of my archive works fine. But exactly these three folders fail:
.Archiv.merk.Versicherungen.Axa (Reiserücktritt)
.Archiv.merk.Versicherungen.Bavaria_Haftpflicht
.Archiv.merk.Versicherungen.LVM_AuslandsreisekrankenversicherungIn Thunderbird, I see the message headers, but when I try to open a message, the body stays empty. On the server, the files are intact – head shows the full header, and the messages are readable as plain files. Other folders with similar special characters (e.g. &APw-, &AOQ-, &ANY-) work without problems. So I don't think the special characters are the cause.
Problem 3: doveadm mailbox list shows only INBOX and Trash. Even though the maildir contains many dot‑prefixed subfolders, doveadm mailbox list -u mailuser returns only: text
Trash INBOX
In Thunderbird, the subfolders appear inside INBOX (e.g. INBOX.Archiv, INBOX.Archiv.Reisen), which is basically correct. But doveadm does not list them as separate mailboxes.
What I have already tried (without success):
Renaming the three problematic folders to simple names (e.g. Axa_Reiseruecktritt) and creating new folders with the copied mails.
Deleting Dovecot index files (dovecot.index*, dovecot-uidlist, subscriptions) and restarting Dovecot.
Changing namespace separator and prefix settings.
Adding dovecot to mailuser group and adjusting permissions (chmod 750).
Forcing Thunderbird to re‑synchronize by deleting local .msf files – after that, the three folders sometimes disappear or become empty in Thunderbird, but the mail files remain on disk.None of this made doveadm mailbox list show the subfolders, and the three folders remain unreadable.
My questions:
Why does doveadm mailbox list not show the subfolders, even though they exist as dot‑prefixed directories and Thunderbird displays them? What do I need to change so that Dovecot lists them properly?
Why can I not move, delete, or rename any folder via IMAP, even though moving messages works? Is this a configuration issue (e.g. missing ACL, wrong permissions, or something with the namespace)?
How can I make the three unreadable folders readable again? What is the safest way to rebuild their indexes or re‑create them so that Thunderbird can open the messages?
If the folder names are problematic (e.g., due to length or special characters), what is the correct way to rename them in the maildir structure so that Dovecot and Thunderbird can handle them normally? I need a method that preserves the existing mails and the folder hierarchy.I would be very grateful for any hints, because I'm stuck and have already spent many hours on this.
Thank you in advance.
"rdorau---" == rdorau--- via dovecot <dovecot@dovecot.org> writes:
Those mail_home and mail_path variables look wrong to me. You need to check the dovecot migration docs, and also try out the online conversion tool.
The configuration language on dovecot 2.4 has changed quite a bit and needs alot of tweaking to move from 2.3 to 2.4 versions.
https://doc.dovecot.org/2.4.1/installation/upgrade/2.3-to-2.4.html
I'm running Dovecot 2.4.1 on a Raspberry Pi 4 with DietPi (Debian 13, ARM64) and had to migrate from another OS with Dovecot 2.3. My maildir is at /var/mail/mailuser. It contains many dot‑prefixed subfolders, e.g. .Archiv, .Archiv.Reisen, .Sozio. Relevant parts from doveconf -n: text
dovecot_config_version = 2.4.0 auth_mechanisms = plain login dovecot_storage_version = 2.4.0 listen = * login_trusted_networks = 192.168.178.0/24 mail_driver = maildir mail_home = /var/mail/%u mail_path = /var/mail/%u protocols = imap ssl = no passdb pam { driver = pam } userdb passwd { driver = passwd } namespace inbox { inbox = yes prefix = separator = . }
Problem 1: Cannot move, delete, or rename any folder via IMAP. In Thunderbird, I can move individual messages between folders, but I cannot move, rename, or delete any folder itself. This affects all folders, not just specific ones. Right‑clicking a folder and choosing “Delete”, “Rename”, or dragging a folder to another location does nothing – no error, just no effect. I have checked permissions on the maildir; mailuser owns the directories and files, and dovecot is in the mailuser group.
Problem 2: Three specific folders cannot be opened (message body not loaded). Most of my archive works fine. But exactly these three folders fail:
.Archiv.merk.Versicherungen.Axa (Reiserücktritt)
.Archiv.merk.Versicherungen.Bavaria_Haftpflicht
.Archiv.merk.Versicherungen.LVM_Auslandsreisekrankenversicherung
In Thunderbird, I see the message headers, but when I try to open a message, the body stays empty. On the server, the files are intact – head shows the full header, and the messages are readable as plain files. Other folders with similar special characters (e.g. &APw-, &AOQ-, &ANY-) work without problems. So I don't think the special characters are the cause.
Problem 3: doveadm mailbox list shows only INBOX and Trash. Even though the maildir contains many dot‑prefixed subfolders, doveadm mailbox list -u mailuser returns only: text
Trash INBOX
In Thunderbird, the subfolders appear inside INBOX (e.g. INBOX.Archiv, INBOX.Archiv.Reisen), which is basically correct. But doveadm does not list them as separate mailboxes.
What I have already tried (without success):
Renaming the three problematic folders to simple names (e.g. Axa_Reiseruecktritt) and creating new folders with the copied mails.
Deleting Dovecot index files (dovecot.index*, dovecot-uidlist, subscriptions) and restarting Dovecot.
Changing namespace separator and prefix settings.
Adding dovecot to mailuser group and adjusting permissions (chmod 750).
Forcing Thunderbird to re‑synchronize by deleting local .msf files – after that, the three folders sometimes disappear or become empty in Thunderbird, but the mail files remain on disk.
None of this made doveadm mailbox list show the subfolders, and the three folders remain unreadable.
My questions:
Why does doveadm mailbox list not show the subfolders, even though they exist as dot‑prefixed directories and Thunderbird displays them? What do I need to change so that Dovecot lists them properly?
Why can I not move, delete, or rename any folder via IMAP, even though moving messages works? Is this a configuration issue (e.g. missing ACL, wrong permissions, or something with the namespace)?
How can I make the three unreadable folders readable again? What is the safest way to rebuild their indexes or re‑create them so that Thunderbird can open the messages?
If the folder names are problematic (e.g., due to length or special characters), what is the correct way to rename them in the maildir structure so that Dovecot and Thunderbird can handle them normally? I need a method that preserves the existing mails and the folder hierarchy.
I would be very grateful for any hints, because I'm stuck and have already spent many hours on this.
Thank you in advance.
dovecot mailing list -- dovecot@dovecot.org To unsubscribe send an email to dovecot-leave@dovecot.org
Hello,
I'm running Dovecot 2.4.1 on a Raspberry Pi 4 with DietPi (Debian 13, ARM64). My maildir is located at /var/mail/mailuser. The directory contains many dot-prefixed subfolders, e.g. .Archiv, .Archiv.Reisen, .Sozio, .Marla. The mail files themselves are intact.
My current doveconf -n output looks like this: text
dovecot_config_version = 2.4.0 auth_mechanisms = plain login dovecot_storage_version = 2.4.0 listen = * login_trusted_networks = 192.168.178.0/24 mail_driver = maildir mail_home = /var/mail/%u mail_path = /var/mail/%u protocols = imap ssl = no passdb pam { driver = pam } userdb passwd { driver = passwd } namespace inbox { inbox = yes prefix = separator = . }
Problem 1: doveadm mailbox list -u mailuser returns only INBOX and Trash. The dot-prefixed subfolders are not recognized. In Thunderbird, the subfolders appear inside INBOX (e.g. INBOX.Archiv, INBOX.Archiv.Reisen), but doveadm does not list them as separate mailboxes.
Problem 2: I cannot move, delete, or rename any folder via IMAP. In Thunderbird, I can move individual messages, but I cannot move, rename, or delete any folder. This affects all folders.
What I have already tried (without success):
Renaming the three problematic folders to simple names and copying the mails into new folders
Deleting Dovecot index files (dovecot.index*, dovecot-uidlist, subscriptions) and restarting Dovecot
Changing separator and prefix settings
Adding dovecot to mailuser group and adjusting permissions (chmod 750)
Forcing Thunderbird to re-synchronize by deleting local .msf files – after that, the three folders sometimes disappear or become empty in Thunderbird, but the mail files remain on disk
Moving all dot-prefixed folders into a Maildir subdirectory and adjusting mail_path accordinglyNone of this made doveadm mailbox list show the subfolders, and the three folders remain unreadable.
My questions:
Why does doveadm mailbox list not show the subfolders, even though they exist as dot-prefixed directories and Thunderbird displays them? What do I need to change so that Dovecot lists them properly?
Why can I not move, delete, or rename any folder via IMAP, even though moving messages works? Is this a configuration issue?
How can I make the three unreadable folders readable again? What is the safest way to rebuild their indexes or re-create them so that Thunderbird can open the messages?Additional note: I do not have access to the online conversion tool. I would be very grateful if someone could post the minimal, correct Dovecot 2.4 configuration for my setup. My maildir is at /var/mail/mailuser/ and contains dot-prefixed subfolders. My goal is to see these folders in Thunderbird and doveadm mailbox list without a double INBOX.
Thank you in advance for your help.
Hi!
2.4 does no longer support %u, see https://doc.dovecot.org/2.4.5/installation/upgrade/2.3-to-2.4.html#variable-...
Aki
On 30/08/2026 01:52 EEST rdorau--- via dovecot <dovecot@dovecot.org> wrote:
Hello,
I'm running Dovecot 2.4.1 on a Raspberry Pi 4 with DietPi (Debian 13, ARM64). My maildir is located at /var/mail/mailuser. The directory contains many dot-prefixed subfolders, e.g. .Archiv, .Archiv.Reisen, .Sozio, .Marla. The mail files themselves are intact.
My current doveconf -n output looks like this: text
dovecot_config_version = 2.4.0 auth_mechanisms = plain login dovecot_storage_version = 2.4.0 listen = * login_trusted_networks = 192.168.178.0/24 mail_driver = maildir mail_home = /var/mail/%u mail_path = /var/mail/%u protocols = imap ssl = no passdb pam { driver = pam } userdb passwd { driver = passwd } namespace inbox { inbox = yes prefix = separator = . }
Problem 1: doveadm mailbox list -u mailuser returns only INBOX and Trash. The dot-prefixed subfolders are not recognized. In Thunderbird, the subfolders appear inside INBOX (e.g. INBOX.Archiv, INBOX.Archiv.Reisen), but doveadm does not list them as separate mailboxes.
Problem 2: I cannot move, delete, or rename any folder via IMAP. In Thunderbird, I can move individual messages, but I cannot move, rename, or delete any folder. This affects all folders.
What I have already tried (without success):
Renaming the three problematic folders to simple names and copying the mails into new folders Deleting Dovecot index files (dovecot.index*, dovecot-uidlist, subscriptions) and restarting Dovecot Changing separator and prefix settings Adding dovecot to mailuser group and adjusting permissions (chmod 750) Forcing Thunderbird to re-synchronize by deleting local .msf files – after that, the three folders sometimes disappear or become empty in Thunderbird, but the mail files remain on disk Moving all dot-prefixed folders into a Maildir subdirectory and adjusting mail_path accordinglyNone of this made doveadm mailbox list show the subfolders, and the three folders remain unreadable.
My questions:
Why does doveadm mailbox list not show the subfolders, even though they exist as dot-prefixed directories and Thunderbird displays them? What do I need to change so that Dovecot lists them properly? Why can I not move, delete, or rename any folder via IMAP, even though moving messages works? Is this a configuration issue? How can I make the three unreadable folders readable again? What is the safest way to rebuild their indexes or re-create them so that Thunderbird can open the messages?Additional note: I do not have access to the online conversion tool. I would be very grateful if someone could post the minimal, correct Dovecot 2.4 configuration for my setup. My maildir is at /var/mail/mailuser/ and contains dot-prefixed subfolders. My goal is to see these folders in Thunderbird and doveadm mailbox list without a double INBOX.
Thank you in advance for your help.
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participants (3)
-
Aki Tuomi
-
John Stoffel
-
rdorau＠gmx.de