The IMAP command "CREATE" failed with server error: Unknown namespace

[Astral God]

Hi.

One of my users is getting this error when he tries to create a folder on the IAMP trough Apple Mail:

The IMAP command "CREATE" failed with server error: Unknown namespace

I've found this topic for Debian, but how can i fix this on cPanel ?
cooper’s Home » Blog Archive » Apple Mail.app error with Dovecot IMAP (Debian 4.0 etch)

 

[Infopro]

Not sure if this is helpful or not, but find out what the user has set in Mail > Preferences > Accounts > Select the proper account > Advanced tab > IMAP Path Prefix:

 

[Astral God]

Hi Infopro.

My user tells me that this value (IMAP Path Prefix) is empty.
Thanks.

 

[Infopro]

Mine says: INBOX

 

[Astral God]

OK, and you're able to create folders ?

 

[Infopro]

Yes. Normal IMAP account. I'm on multiple email lists and have rules to move mail to each of the created folders and those folders and mail are synced across all devices as expected.

Check this, again, not sure this is helpful but take a peek.

Login to Webmail, click Horde and log in. (skip maintenance if asked) Find Options on top of page. Find Server and Folder Information. Check settings here.