[JPAres1]

@mercime, thank you for your response. We were getting ready to try your suggestion when this happened:

As you know, the registration emails going out from our site were working but then weren’t working. See previous email. Since then, we went into something we never before went into: Membership, Communications and created a test Welcome message. We registered as a new user and wouldn’t you know we received the registration activation email as that new user, the test Welcome message for the new user and the admin new user notification email. Then we deactivated the test Welcome message and went through the process again. It worked! We received two emails now (just like before the mysterious site-rendered email disappearance); the registration activation email as that new user and the admin new user notification email. We then completely deleted the test Welcome message so that the Membership, Communications was the same as before we started and again, we received the same two emails. Whatever did we reactivate?

So, for whatever reason, the emails seem to be working again. However, this is a huge concern to us. This could happen again and we would have no idea why the emails stopped working and why it suddenly reset itself. We have repeatedly read in our research of this matter that WordPress uses PHPMail Sendmail. It has been mentioned more than once that making the emails go SMTP is better and more stable. We are of the belief that this may be the core issue here. Can anyone give input on this and guide us in the right direction? Is there anyone out there that can explain to us what may have happened and is there something we need to hard code so that it doesn’t happen again?

Many thanks for your help and advice.