Sadly, yes ... a know problem that we wrestle with.  Our worker server can and does send out emails, but some receiving hosts and relays recognise (rightly) that those emails are from automated systems and thing they may be spam.  There have always been occasional issues, but they are far more marked now that our worker service has a new name and the forum is cloaked by a receptionist who has inherited the old name.   Thus is superb in helping with loading, and with us now running https, but not helpful on sending out automated emails - they DO go out, but some services such as gmail default to rejecting them.    Always a topic on my list to keep in review and to see what we can do so make for a cleaner automatic emailer on limited time and experience. 

Nice to know I am harmless 

I will have a look later ... but in turn it may not be today as I have five times appointments / meetings

There is a difference between how I send emails on things like MTUG and how the server sends email. 

Mine come from my laptop via an email service to which I regularly log in. It knows I am a human with all sorts of checks in place and provided I continue to pass those checks I'm OK; it's the same for outgoing emails from services like - yes - your gmail (and btinternet and so on) accounts and done for you by those services. 

Coffee Shop automated emails do not have the same human checks nor can we easily have them piggy-back on either my normal account nor on gmail of something else and that means we are not under their protective and very carefully set up and maintained umbrella.  We need to / could / perhaps set up an umbrella ourselves so that outgoing emails from us appear to be / are dry - but that is in amongst lots of spammers using servers we need to be better than them and prove we are not a spammer.   There are potential routes but it ain't easy.   I am very much aware of the issue though not as knwledgable as 000s of other who include the spammers.

You know, I know, and I know you know    ... my comment was directed to other readers of this thread (you are far from alone in this issue) to help clarify it for them too.