+++ This bug was initially created as a clone of Bug #1512053 +++

In bug 1512053 I learned that the dovecot server supports slash in folder names provided the "listescape" plugin is enabled in the dovecot server. This allows a user to create a folder called, for example, "Reports for 2018/2019". Tb also allows the creation of folders with a slash by using the '^' substitute character, e.g., when creating a folder you would enter "Reports for 2018^2019". (Note also, for this to work the folder separation delimiter must be set to something other than slash in dovecot. Backtick`is a possible choice. Also, in tb a literal ^ is entered with double ^, i.e.,^^.)

Tb creates the folder with slash in the name and displays it properly and message can be place in it. However there are problems when opening a message with attachments in the folder in that tb essentially freezes when an attachment is opened. There may also be other problems when accessing the folder that I have not yet identified.

I have found a tentative fix for opening the attachment but I need to test other cases to make sure the folder containing slashes in its name and the messages inside the folder behave normally.

Note: Bug 1512053 will explore the possibility to allow the user to directly enter "/" as a valid folder character instead of creating two folders, possibly enabled with a new user pref. But regardless of whether that change is made, the bug described in this comment still exists.

Any luck with the testing?

I think a better solution for having a slash in a folder name is to enter the unicode slash. It gets encoded correctly even if UTF-8 is not supported thanks to default MUTF-7 encoding. Also, it doesn't depend on what the imap server uses for separation delimiter, unlike when "^" is used.

To enter the unicode style slash in linux when creating a folder you type ctrl-shift-u, then 2215, and then spacebar and the slash appears. I know there is a similar entry method for windows and mac but not sure what they are.

Example, today's date (using unicode 2215 slashes): 1∕18∕2022.

There is no detrimental effect on attachments when using the unicode 2215 style slash.

I have found a tentative fix for opening the attachment but I need to test other cases to make sure the folder containing slashes in its name and the messages inside the folder behave normally.

I don't remember what my "tentative fix" for the attachment issue was. (The problem still exists when I create a folder with ascii slashes using "^".) In any case, I would recommend just setting this bug, like the associated bug 1512053, to wont fix.