Comment 2 for bug 265973

I encountered this bug repeatedly when I was using 'arch' to
import an old, non-mailman mbox file which contained
messages with subjects of "Re:" or "Re: ".
HyperArch.py
strips the Re: off the subject line, but when it does so, it
does not check for an empty string... it assumes that the
empty-string check happens earlier in the mail path, which
for normal mailman messages, it does.

The only time (that I can think of) you would encounter this
bug is when you are importing non-mailman correspondence in
via the 'arch' command. This situation is not uncommon when
converting old mailing lists to mailman.

If you still want sample messages that caused this bug at
our site, I can provide them, though it is trivial to set up
an mbox-formtted message matching this description by
manually editing the subject line.