Description:
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Requested in http://mlmmj.org/archive/mlmmj/2016-10/0000002.html.
TL;DR: the local part of mailing list subscription confirmation addresses
formed of:
mailing-list-name "+confsub-" 16-random-hex "-" sender-address
can get very long, especially if sender-address is long. However, RFC limits it
at 64 characters.
So I'm suggesting to drop the sender-address part from this address, since it
is stored in the related file anyway and the atomic file creation secures the
random from collisions anyway.