On 15 Jan 2020, at 05:56, Sam Tuke <s...@lightmeter.io> wrote: > I noticed that newsletters which I receive from large firms are typically > sent from servers which have port 25 closed.
And this is an issue why? > Is it common practice to close port 25 on bulk sending servers? Should we do > this for Postfix servers which serve the same role? What's the advantage? It is common to not have port 25 open on any machine that does not receive mail. > Maybe the MTAs that such senders use are so customised as to be capable of > only sending, not receiving, mail? That is not “highly customize”; that is a very normal setup for large installs. -- "Are you pondering what I'm pondering?" "Well, I think so hiccup, but Kevin Costner with an English accent?”
