i have two very major issues with the way the subject
of incoming email messages is parsed/handled:

(1) if there is a 10 year old issue with subject "XYZ"
and a new mail with subject "XYZ" comes in, it reopens
that old and probably unrelated issue.
It isn't so hard in a specific environment for users to
open issues with rather generic & useless subjects
which are eventually reused over time.  (This is
especially true when they reply to automated mail
messages which carry a static subject.)

While i understand the desire to handle:
  UserA sends mail to roundup & UserB w/ subject "ABC"
  UserB group replies w/ subject "Re: ABC"
In that very particular case, yes, it is good of
roundup to lump the two mails in the same issue, but
it's done by guessing which lacks precision.

i'd rather lose this nicety than have it in its current
form.

(2) mails sent to roundup cannot contain [ABC] in
subject.  I'm not sure how this should be dealt with,
but it's very furstrating (especially for new issues
being submitted) to get rejections such as:
The class name you identified in the subject line
("host.foo.bar") does not exist in the
database.

Valid class names are: category, file, issue, keyword,
msg, priority, query, status, user
Subject was: "[host.foo.bar] test"

i cannot control the format of all subjects, and the
current scheme used by roundup to receive commands
really gets in the way a times.