Log Message:
Update DBMail to 2.0.11, the latest bugfix maintenance release on the 2.0.x
branch.  There are a number of changes, see the ChangeLog for details.

Note that in the meantime, 2.2.x is the new stable release series, bringing
many new features e.g. LDAP authentication, header caching, Sieve mail
filtering, ... but I'll leave that update to a more experience DBMail user.