I recommend making a post in our #marketplace category and offer money for someone to fix your install for you.
@Rohit_Manglik sent me his Discourse admin credentials, and I played around a bit.
From the Discourse side, mail sending appears to be fine. Both test and signup mails are recorded as having been sent, and are received if sent to Mail Tester.
Mail Tester says that email deliverability is good, 8.5 / 10, with the only issue of being listed in 2 blacklists.
Still, I’ve been unable to get any email, test or signup, delivered to my inbox or even my spam folder. My mail provider has let through mails with way worse deliverability, so I’m quite certain that that isn’t the problem.
This leaves SparkPost as the only reasonable suspect. Try logging in to your SparkPost account and see whether you find anything interesting – maybe they are lacking payment information? (I could imagine they have special handling for mails to mail-tester.com.) If in doubt, try contacting their support, and tell them that you are certain that you deliver mails to them, and they show up if sent to mail-tester.com, but you failed to receive them if sent to any normal address.
Breaking news: I just got both a test and a signup mail delivered to my inbox. Assuming you haven’t changed anything yet, this means that mail is actually working, but quite slow - either on the SparkPost side, or because it triggers GMail’s delayed delivery for suspect mails for some reason.
Thanks a lot for debugging.
I tested again and can confirm that I received confirmation email. (It was not working at least when SSL issue was not resolved).
However, now when I tried to send an email to change my email address from the default one, I did not receive any email.
Any pointers please.
Over the last hour, I continued receiving test mails I had requested earlier.
Since GMail’s spam mail delay is only a few minutes, this basically leaves only SparkPost as the culprit, so I really suggest contacting their support, or changing mail providers.