Author: D. J. Bernstein Date: To: exim-users Subject: Re: [Exim] Re: Spam Control
Suresh Ramasubramanian writes: > qmail loves to do things different. They use - where most other MTAs
> use + :)
In fact, the first two major MTAs to support automatic subaddressing by
default were MMDF and qmail. MMDF used =.
I used - as the default delimiter in my addalias program in 1993, and
then in qmail in 1995, because it fit perfectly with other common uses
of hyphens. Of course, qmail can use any delimiter character.
It was, and is, inconvenient to support - in sendmail, because dividing
names at non-special characters is a pain, and making - special would
break deliveries to hyphenated usernames. This is why sendmail started
using +.
