[Dovecot] Easy way to make all mailboxes of a user read-only

[Stephan von Krawczynski]

Hello all,

I try to configure dovecot to make all imap accesses read-only for a certain
user. I thought this would be possible by creating a global acl file (here
"global-acl") like:

user=<username> lr

and 

plugin {
  acl = vfile:/etc/dovecot/global-acls:cache_secs=300
}

But that seems to be ignored. What is wrong with this idea, the docs are not
really clear about a single acl file with global settings.

-- 
Regards,
Stephan