On 5 Mar 2019, at 9:10, Ryan McClung via Exim-users wrote:
> Why use only 465 and not 587? Just curious there.
Or why not every port between 400 and 10000? :)
The way daemons on ports 465 and 587 can be expected to behave are
defined in IETF RFCs 6409 and 8314. If you want your mail system to be
interoperable with the broadest possible range of legitimate mail
software, it is a good start to follow the RFCs.
There's a very arcane and confusing history behind the use of port 465
which makes it wise, at least for a few more years, to continue to
support port 587 with STARTTLS.
--
Bill Cole
bill@??? or billcole@???
(AKA @grumpybozo and many *@billmail.scconsult.com addresses)
Available For Hire:
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