Strange email folder naming behavior/errors

[imc67]

Today I wanted to migrate a Gsuite email box to Cloudron. The box contained about 12GB/45k mails in about 50 folders.

The naming convention of the folders were like:

01. "main"
01.01. "sub 1" (not nested)
01.02. "sub 2" (not nested)

In an email client I tried to move such a folder from current box to new box. This went awfully wrong!

I checked Roundcube what was/wasn't created in Cloudron:

folder named 01
... nested folder named: 01
... ... nested folder named: "sub 1" (Nested)

In the first 2 folders you're not able to store mails, only in the "last" one and the emails didn't got moved (actually they disappeared).

When creating such a folder in Roundcube you get an error that a . "dot" is not allowed.

Isn't it very strange that you're not able to use dots in a folder name and that it creates subfolders based on those dots when created in a client?

The only workaround was to rename in Gsuite all the 50 folders and then folder by folder move everything and double double check if everything moved correctly.

Kind regards,

Marcel.

[murgero]

@imc67 IMAP is funky with special characters in folder names, especially with Outlook. Avoid using !@#$%^&*(){}[]:;"'<>?/|\ Periods are gonna be hit or miss, so avoid those as well. Instead, dashes and Underscores should work:

01_01-02
01_01-03

etc etc

I'd like to point out that this is an issue with IMAP and not cloudron.

[imc67]

@murgero aha, then Gsuite/Gmail is able to do this, will take note of this.

[murgero]

@imc67 gsuite / gmail is not IMAP, just to note. They support an IMAP-compatible system for syncing to Outlook and other mail clients, but gmail itself is not IMAP.

[girish]

Gmail import is a complicated topic and as @murgero said gmail has a IMAP compat layer but it's internal storage is not IMAP.

See https://imapsync.lamiral.info/FAQ.d/FAQ.Gmail.txt for detailed overview of importing. Also, I am not on expert on this topic since this is a bit outside the scope of Cloudron.

[girish]

BTW, for the "dot" thing, the mailbox separator in Cloudron is ".". This is why folders with dot don't work. If you create a folder named "foo.bar.baz", it is like subfolder bar under foo and subfolder baz under bar.

While using "." as a seperator is not a bug as such, using "/" as a separator instead of "." would have been a better choice for Cloudron but we didn't know this when we started (sadly, "." is the dovecot default too). And also using "/" as separator is required for mailbox sharing to work. We are slowly working towards moving the separator to be "/", step by step.