Handling slashes "/" in folder names about imapsync

[gilleslamiral]

Well thats crazy: --f1f2 "Slash/Test=Slash-Test" says there is no folder on host1.

--f1f2 is picky, the Slash/Test folder has to exist verbatim, ie, as shown in the folders listing.

https://imapsync.lamiral.info/README

     --f1f2    str1=str2 : Force folder str1 to be synced to str2,
                           --f1f2 overrides --automap and --regextrans2.
                           Use several --f1f2 options to map several folders.
                           Option --f1f2 is a one-to-one-only folder mapping,
                           and str1 and str2 must be full path folder names.
                           Use --regextrans2 for more general mappings.

I updated
https://imapsync.lamiral.info/FAQ.d/FAQ.David_Tobit.txt

Q. There are slashes / in folder names that are not separators. How can
   I keep them or change them in the destination account with imapsync?

A. You can't do it properly with imapsync or any other IMAP client.

   By default, imapsync will consider those / characters as separators
   and get empty folders where they stand.  If you change "/" to
   another character, say "_", with --regextrans2, then all / are
   transformed to _ and the folder hierarchy disappears.
   
   Solution? Yes. Change the / on the source account manually, using
   the same email tool that allowed to create them, the David Tobit
   native email client tool.

   See https://github.com/imapsync/imapsync/issues/440

[gilleslamiral]

I'm curious about how the slashes are represented in IMAP in David Tobit.
Can you show the beginning of the output, the part "Host1: folders list"?

Host1: folders list (first the raw imap format then the [X] = [Y]):
* LIST (\HasNoChildren) "." Spam
* LIST (\HasNoChildren) "." Entw&APw-rfe
* LIST (\HasNoChildren \Drafts) "." Drafts

Try this:

imapsync ...  --create_folder_old

[rcbebo82]

Output:

Host1: folders list (first the raw imap format then the [X] = [Y]):
* LIST () "/" "INBOX/GPR/GPA"
* LIST () "/" "INBOX/GPR/GPA/Bilanz"
* LIST () "/" "INBOX/GPR/GPA/Rechnungen "
* LIST () "/" "INBOX/GPR/GPA/GPA Logo neu"
* LIST () "/" "INBOX/GPR/GPA/Steuerbescheide"
* LIST () "/" "INBOX/Haus Autunstra&AN8-e"

Currently trying your suggest "--create_folder_old".

[rcbebo82]

--create_folder_old does not change the behavior
David:

Outlook:

[gilleslamiral]

You're doomed to

• ask the user to convert his slashes to another character before the migration.
• or ask him for the list of all his slashed folders and use imapsync options --regextrans2 or even --f1f2 to change them.

[rcbebo82]

Well thats crazy: --f1f2 "Slash/Test=Slash-Test" says there is no folder on host1. So it seems the only possibility is to rename them on host1 before the sync.
I also did some further research and it seems that this is a known problem with David Mailserver. The David native client displays these folders correct but the imap implementation screws it up. Found several entries of email archiving systems which had the same problem. They also mentioned that the folders on the David had to be renamed in first place.
Thx @gilleslamiral , maybe this post makes people aware of this problem.