So i use spf, dkim (both old and new) and dmarc [in a limited sense, all links to this blog] and we are considering adsp and that seems to be unknown to most except by three people. There not hard although i would claim that since i have running these components with email for years.
If you have a decent provider of email they will check for these things. Most likely they will not bother to. Auto responders are the worse, and if your microsoft ‘acredited’ your probably wondering what dkim* is.
Some email servers are in a shit state. Oddly i like email even with its after the fact upgrades but it would be ‘nice’ if i did not have remove bits of my config like bley so we can receive email from an idiot who has neither spf, dkim every once in a while.
We don’t have too many issues with crap coming inbound but it seems as if things are getting worse, and while we are happy to adjust the recipe to be with the times it is the values i find disturbing. Yes i can virus scan and detect spam to keep the crap out.
So if you ‘manage’ an email server without the hard stuff you have never heard of please get another job.
* not a banana