Apple Mail and subfolders

[Filip Hajný]

> I just created a subfolder in Apple mail. It shows up on the server as .list.Subfolder
> I drug your message into the folder, and the message shows up in Mail.app and shows up in the subfolder on the server
> 
> # ls -lnR .lists.Subfolder                          [10:40] [/usr/local/virtual/kremels at kreme.com/Maildir]
> total 56
> drwx------  2 89  89   512 Jul 11 10:41 cur
> -rw-------  1 89  89    21 Jul 11 10:41 dovecot-keywords
> -rw-------  1 89  89   109 Jul 11 10:41 dovecot-uidlist
> -rw-------  1 89  89  1924 Jul 11 10:41 dovecot.index.cache
> -rw-------  1 89  89   868 Jul 11 10:41 dovecot.index.log
> -rw-------  1 89  89     0 Jul 11 10:35 maildirfolder
> drwx------  2 89  89   512 Jul 11 10:35 new
> drwx------  2 89  89   512 Jul 11 10:41 tmp
> 

I’ve created a test server and found out that the driving factor is what the namespace `separator` is set to. If set to /, Apple Mail gets confused and URL-encodes it when creating a new folder. If the separator is blank (as set by default) or set to e.g. a dot, everything works just fine.

Based on example and docs I found, a slash character should be good or even recommended, suggesting this is some kind of bug in Apple Mail,  but I’m not versed enough in the IMAP related RFCs to understand.

>> 
>> This definitely used to work fine in the past.
>> 
>> Running 2.3.10.1 as part of the Mailcow suite.
> 
> I'm not familiar with that. Is that running dovecot on your Mac? My server is a FreeBSD 12.1 machine running dovecot-2.3.10.1_2.

Mailcow is a suite of server SW based on Dovecot & Postfix, intended to provide a full-featured mail server. In effect I’m running Dovecot in a Docker container on Alpine Linux.

-F