Resolved Dovecot Broken After Latest Update

[scpcomp]

Server operating system version

Ubuntu 22.04.4 LTS

Plesk version and microupdate number

18.0.61 #4

Last night Dovecot was updated to 2.3.21-v.ubuntu.22.04+p18.0.61.0+t240426.1307, and I am now getting these errors:

dovecot [3425360]

service=imap, user=tim@xxxx.co.uk, ip=[nnn.nnn.nnn.nnn]. Error: namespace configuration error: list=yes requires prefix=INBOX. to end with separator /

Dovecot.conf

## Dovecot configuration file

# PLEASE DON'T EDIT ANYTHING IN THIS FILE! ANY CHANGES WILL BE LOST ON UPGRADE.
# Instead add your custom configuration to /etc/dovecot/conf.d/
# See the end of this file for details on customization.

# See example configuration files in /usr/share/doc/dovecot/example-config/
# See stock configuration files in /usr/share/doc/plesk-dovecot/dist-config/


# Space separated list of wanted authentication mechanisms.
# NOTE: See also disable_plaintext_auth setting.
auth_mechanisms = plain login digest-md5 cram-md5 apop

# Valid UID range should include popuser.
first_valid_uid = 30

# List of allowed characters in username. "'&" is added here to the default list.
auth_username_chars = abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890&.-_@'

# Plesk Maildirs layout.
mail_home = /var/qmail/mailnames/%Ld/%Ln
mail_location = maildir:/var/qmail/mailnames/%Ld/%Ln/Maildir:UTF-8

# Enable Maildir++ quota support.
mail_plugins = $mail_plugins quota

plugin {
  # Take quota limits from maildirsize file. If it doesn't exist, don't enforce.
  quota = maildir:User quota
  # LDA/LMTP allows saving the last mail to bring user from under quota to
  # over quota, if the quota doesn't grow too high. Default is to allow as
  # long as quota will stay under 10% above the limit. Also allowed e.g. 10M.
  # 0 doesn't allow going over quota (compatibility with Courier-IMAP behavior).
  quota_grace = 0
}


service auth {
  # Allow userdb lookups for popuser.
  unix_listener auth-userdb {
    mode = 0600
    user = popuser
    group = popuser
  }
}

service stats {
  unix_listener stats-writer {
    user = popuser
  }
}

# PEM encoded X.509 SSL/TLS certificate and private key.
ssl_cert = </etc/dovecot/private/ssl-cert-and-key.pem
ssl_key =  </etc/dovecot/private/ssl-cert-and-key.pem


# Protocols support.

protocols = imap pop3

protocol imap {
  mail_plugins = $mail_plugins imap_quota
}

protocol pop3 {
  # POP3 UIDL format similar to the one used by Courier-IMAP.
  pop3_uidl_format = UID%u-%v
}

# Applicable workarounds for various client bugs.
imap_client_workarounds = delay-newmail
pop3_client_workarounds = outlook-no-nuls oe-ns-eoh


# Default private namespace setup compatible with Courier-IMAP.

namespace inbox {
  separator = .
  prefix = INBOX.
  inbox = yes

  mailbox Sent {
    auto = subscribe # autocreate and autosubscribe the Sent mailbox
    special_use = \Sent
  }
  mailbox Spam {
    auto = create # autocreate Spam, but don't autosubscribe
    special_use = \Junk
  }
  mailbox Drafts {
    auto = create
    special_use = \Drafts
  }
  mailbox Trash {
    auto = create
    special_use = \Trash
  }
}


# Logging verbosity and debugging.

# Log unsuccessful authentication attempts and the reasons why they failed.
#auth_verbose = yes

# In case of password mismatches, log the attempted password. Valid values are
# no, plain and sha1. sha1 can be useful for detecting brute force password
# attempts vs. user simply trying the same password over and over again.
#auth_verbose_passwords = no

# Even more verbose logging for debugging purposes.
#auth_debug = yes

# In case of password mismatches, log the passwords and used scheme so the
# problem can be debugged. Enabling this also enables auth_debug.
#auth_debug_passwords = yes

# Enable mail process debugging. This can help you figure out why Dovecot
# isn't finding your mails.
#mail_debug = yes

# Show protocol level SSL errors.
#verbose_ssl = yes


# Log format compatible with Plesk statistics collector.
mail_log_prefix = "service=%s, user=%u, ip=[%r]. "
pop3_logout_format = "rcvd=%i, sent=%o, top=%t/%p, retr=%r/%b, del=%d/%m, size=%s"
imap_logout_format = "rcvd=%i, sent=%o"

# Customizable part of configuration gets included below. The filenames are
# first sorted by their ASCII value and parsed in that order. The 00-prefixes
# in filenames are intended to make it easier to understand the ordering.
#
# Prefixes 10 through 20 and 90 through 95 (inclusive) are reserved for Plesk.
# Please do not occupy them or edit files with these prefixes!
!include conf.d/*.conf

# vim:ts=2 sts=2 sw=2 et:

We also have a custom file to set the folder structure for mailboxes to be the same as we had on our old server, also running Dovecot:

conf.d/50-custom.conf

mail_location = maildir:/var/qmail/mailnames/%Ld/%Ln/Maildir:LAYOUT=fs:UTF-8
namespace inbox {
  separator = /
  inbox = yes

  mailbox Sent {
    auto = subscribe # autocreate and autosubscribe the Sent mailbox
    special_use = \Sent
  }
  mailbox Spam {
    auto = create # autocreate Spam, but don't autosubscribe
    special_use = \Junk
  }
  mailbox Drafts {
    auto = create
    special_use = \Drafts
  }
  mailbox Trash {
    auto = create
    special_use = \Trash
  }
}

Users are reporting they are not receiving emails, and emails are not being sent, they are all sat in the mail queue

 

[learning_curve]

@scpcomp We run the same Ubuntu OS (and Point release), on the same Plesk Obsidian release (and its Point release) and we have exactly the same Dovecot release that you've posted, but... We don't have ANY mail issues of any kind, on any server.

That might indicate that you have a local misconfiguration and looking at your post, it tends to agree with that.
Have you already run Plesk Repair and/or examined the Mail section of Plesk Repair? That might assist.

 

[Kaspar@Plesk]

I suppose it's caused by your custom configuration. You can try to add prefix = INBOX/ or prefix = to your custom configuration to see if that fixes the problem. You'll find more information on namespace configuration in the documentation of Dovecot: Namespaces — Dovecot documentation

 

[scpcomp]

Thank you both for your replies.

It leaves me wondering why it has been working perfectly with the current custom config, and then stopped working after the update.

I'll run the plesk repair and see what it throws up.

 

[scpcomp]

Running plesk repair mail -n did not indicate there were any errors.

Adding prefix = to my custom configuration file however fixed the problems without changing the current mail folder directory structure:
mail_location = maildir:/var/qmail/mailnames/%Ld/%Ln/Maildir:LAYOUT=fs:UTF-8
namespace inbox {
separator = /
inbox = yes
prefix =

mailbox Sent {
auto = subscribe # autocreate and autosubscribe the Sent mailbox
special_use = \Sent
}
mailbox Spam {
auto = create # autocreate Spam, but don't autosubscribe
special_use = \Junk
}
mailbox Drafts {
auto = create
special_use = \Drafts
}
mailbox Trash {
auto = create
special_use = \Trash
}
}

A big thank you to the both of for taking the time to reply and your sound advice.