You cannot force any other party to apply YOUR policy to THEIR systems.
"Your server your rules, but my server my rules" :-)
Furthermore mandatory tls can fail for a bunch of other reasons except
from "not offering tls at all" ex no common cipher/tls version can be
I do mandatory tls on my servers too, but not globally. Just for
Am 02.02.2018 um 09:36 schrieb Peter Keel:
> I get these errors:
> | TLS is required, but was not offered by host mx1.datacomm.ch[188.8.131.52]
> | TLS is required, but was not offered by host relay.kfsb.ch[184.108.40.206]
> Since I've made TLS for SMTP mandatory. The respective admins of these servers
> might want finally at least enable voluntary TLS; some of their customers
> apparently would like to receive mails from my server.
> And by the way, RFC 2487 that is referred to for instance in the postfix
> and stated that one must not make TLS mandatory has been obsoleted by RFC
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