[Dovecot] AuthenticationFailedException: [IN-USE] Couldn't open INBOX: Permission denied

[Earles, Jill]

Thank you very much for the additional context.  

On 2013-05-08, at 9:40 PM, Ben Morrow <ben at morrow.me.uk> wrote:

> At  4AM +0000 on  9/05/13 you (Earles, Jill) wrote:
>> Wow, that is a lot of detail.  Thank you very much.  I appreciate the
>> Unix security perspective - that's something I'm trying to learn more
>> about and be more in tune with as a new systems administrator.  
>> 
>> We are not using dotlocks, and the adduser command does create all the
>> mailbox files with the correct ownership automatically.
>> 
>> I don't know what MTA or MDA are.  
> 
> These are standard mail jargon, so you'll probably come across them
> again. MTA is Mail Transfer Agent, that is, the program which receives
> incoming mail (usually by SMTP) and decides what to do with it.
> Traditionally on Unix this was Sendmail; nowadays it might be Postfix or
> Exim or something instead. 
> 
> MDA is Mail Delivery Agent, and it's the program the MTA hands a mail to
> when it decides to deliver it to a local user. (You may also see LDA,
> Local Delivery Agent, used for the same thing.) Traditionally this was
> often mail(1) or something equally unsuitable; nowadays it might be
> procmail or maildrop or something else. Dovecot provides an MDA called
> 'deliver' or 'dovecot-lda' (they're the same program) which it's often
> worth using if you haven't got a good reason not to.
> 
> Other terms are: MUA, Mail User Agent, which is a program users use to
> read mail; and MSA, Mail Submission Agent, which is the program users
> use to submit new mail for delivery; traditionally this was sendmail(8),
> but now it's more usual to have a special-purpose SMTP server, often
> running on port 587. (Users should not submit mail directly to MX SMTP
> servers, because generally mail needs to be cleaned up before being sent
> off-site.) 
> 
> From the point-of-view of the mail system, a POP/IMAP server like
> Dovecot is considered part of the MUA, the other part being the user's
> actual client; this arrangement, and the corresponding actual-
> client/submission-server split for outgoing mail, is often called
> 'split-client'.
> 
> Ben
>