Comment 1 for bug 680447

There's not much Mailman can easily do about this. The issue is in the Python email library. email.utils.getaddresses() is used by Mailman to get a list of addresses and the length of that list is used as the number of recipients. getaddresses() treats the brackets as a kind of delimiter. Thus, email.utils.getaddresses(['jefke [<email address hidden>]']) returns this list of (name, address) tuples [('', 'jefke'), ('', ''), ('', '<email address hidden>'), ('', '')] of length 4 instead of the list [('jefke', '<email address hidden>')] of length 1 that you expect.

Escaping the brackets as you suggest changes the result only in that a '\' is appended to the <email address hidden> address returned in the third tuple.