Error: Virtual mailbox loops, Dovecot version 2.2.10

[Dan Oriani]

On 04/02/2017 08:26 PM, dan at redchops.com wrote:
> I'm trying to follow the guide at
> https://wiki.dovecot.org/Plugins/Virtual for the 'Conversation' style
> virtual mailbox, but with a small change. I'd like the virtual mailboxes
> to be 'top level', which I found while searching through this list is
> accomplishable by putting the dovecot-virtual file in the root of the
> namespace location. My issue is this works perfectly fine for the All
> Mail virtual mailbox, but the Threaded mailbox fails with the error
> above. I tried creating a RealMail namespace, but that doesn't solve the
> issue either. I feel like I must be overlooking something simple; I
> could get this setup working if the virtual mailboxes shared a namespace
> and were subfolders, but I don't like that setup much (I'm trying to get
> my companies GMail users on to our own webmail client, it's features
> like this that I need to replicate with dovecot or they'll never leave
> their POP3 setups).
> 
> I've attached the output of dovecot -n, and my virtual mailboxes look
> like this:
> 
> # cat Threaded/dovecot-virtual
> All
>  inthread refs x-mailbox INBOX
> 
> # cat all/dovecot-virtual
> RealMail
> RealMail/*
> -RealMail/Trash
> -RealMail/Trash/*
> -RealMail/Spam
> -RealMail/Spam/*
>   all
> 
> I'd appreciate any insight in to this issue. If I try to access the
> Threaded Inbox through IMAP, I get this error specifically:
> a select "Threaded Inbox"
> a NO [SERVERBUG] Virtual mailbox open failed because of mailbox All:
> Internal error occurred. Refer to server log for more information.
> [2017-04-03 00:24:28]
> 
> The relevant line being: Apr  3 00:24:28 mail dovecot:
> imap(dan at redchops.com): Error: Virtual mailbox loops:
> No information before or after.
> 
> Thanks,
> -Dan


Actually, I ended up figuring it out. I removed the RealMail virtual
changing all to just select all from *, set the all mail virtual to
'hidden=yes, list=no' and left the threaded virtual alone and it worked.

Unrelated to this, but since I wanted these folders to be top level, and
thus they're empty namespaces, setting hidden=yes, list=yes on the
threaded virtual allowed it to work correctly with Thunderbird. Without
hidden=yes, Thunderbird complained that the folder didn't exist.

I hope this helps others,

Dan