Hi Lothar,

I haven't yet had the opportunity to go deep into Dovecot engineering / development, (so please correct me if necessary anyone).

I have experienced this exception where attempting to copy mailbox data within a client from IMAP account to IMAP account, but I have not had it cause a mailbox to become inaccessible.

The reason was because Maildir++ format uses the "." separator to delineate child directories, and therefore the character is illegal in mailbox names. The issue was addressed by either changing the filesystem layout to LAYOUT=fs or by changing the mailbox format altogether to e.g. sdbox.

location = maildir:%%h:INDEX=%h/shared/%%u

I can see from your configuration that the LAYOUT is not set as fs, so I would assume is still using Maildir++.

Perhaps this setting was lost during the upgrade?

Regards,

Arnold Opio Oree Chief Executive Officer Parallax Digital Technologies

arnoldoree@parallaxdt.com

http://www.parallaxdt.com

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-----Original Message----- From: Lothar Schilling via dovecot <dovecot@dovecot.org> Reply-To: Lothar Schilling <ls@proasyl.de> To: dovecot@dovecot.org Subject: Character not allowed in mailbox name Date: Mon, 22 Jul 2019 08:33:45 +0200

Hi everybody,

after an update this morning to dovecot 2.3.7 we cannot connect to our shared mailboxes anymore. The error message as issued in Thunderbird:

"Character not allowed in mailbox name '.'"

I didn't change anything about the configuration. Output of dovecot -n:

[...] namespace { list = children location = maildir:%%h:INDEX=%h/shared/%%u prefix = Shared/%%u/ separator = / subscriptions = yes type = shared } [...]

Any help would be appreciated, thank you very much.

Lothar Schilling