[Dovecot] OT: best linux imap client for dovecot

Brian Hayden bhayden at umn.edu
Wed Feb 24 22:30:17 EET 2010

On Feb 24, 2010, at 2:08 PM, WJCarpenter wrote:

>>> Example:
>>> * I have 100's of sent-mail mailboxes I don't want to be  
>>> subscribed to, because it is doubtful I will ever use them. These  
>>> mailboxes are unsubscribed because I don't want to see them in any  
>>> mailbox listings by default.
>> This use of subscriptions is a terrible abuse of IMAP. Like most  
>> terrible abuses, it's a-ok to choose for yourself if you're an  
>> advanced user, but anyone who has done support for a broad user  
>> base knows that a client should *NEVER* act like this as the  
>> default. Subscriptions are brittle and non-portable and hiding  
>> mailboxes based on them leads only to floods of "Where is all my  
>> mail you screwed up my life!!!!" interactions.
> I'm genuinely confused by this come-back.  Could you elaborate?
> Why is having subscriptions (and, specifically, some folders to  
> which you are not subscribed) a terrible abuse of IMAP?  What is non- 
> portable about subscriptions?  The IMAP protocol supports them  
> directly.

Subscriptions themselves aren't an abuse of IMAP, obviously, as they  
are in the spec. A client that *by default* uses them to hide folders  
is abusing them, for exactly the reasons I explained. They are non- 
portable because:

1. The interaction that most (all?) clients poorly bake in between  
subscriptions and the "IMAP root" setting means that if your various  
clients are not configured identically, you'll see one set of folders  
in one place and another set in another. This contributes to users  
thinking mail has disappeared to creating mailboxes with the same name  
at different paths. The latter is annoying to begin with, but becomes  
especially bad when yet another client shows the user both of two same- 
name folders and *resolves them in the interface to the same  
directory*, so the user thinks they are simple duplicates and deletes  

2. Different clients interpolate names differently, such that even if  
two clients are identically configured when it comes to the "IMAP  
root" and  namespaces, they map the subscription to inconsistent paths  
(either on the backend or the in the interface). This is especially  
true of moving between Thunderbird and certain versions of Outlook and  
Vista Mail.

Subscriptions are handy if they're treated more or less like  
bookmarks, or if you only ever use one client, and the client doesn't  
do anything stupid with them. I can't speak for others, but in a large  
university environment that rules out most users with most clients.


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