On Mon 23/Dec/2019 21:03:16 +0100 Keith Moore wrote:
On 12/23/19 2:08 PM, Alessandro Vesely wrote:
Anyway, real SMTP clients use DNS. I'd consider IIoT devices as submission
Color me skeptical. From an idealist perspective I would like such devices
submit mail to MSAs using port 587, or better, TLS over port 465. I'm just
not sure that will fly as there seems to be a lot of mindshare in that world
around submitting mail using port 25.
Serving submission on port 25 is a feasible alternative:
Although most email clients and servers can be configured to use port
587 instead of 25, there are cases where this is not possible or
convenient. A site MAY choose to use port 25 for message submission
by designating some hosts to be MSAs and others to be MTAs.
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