During the February 2021 TFSIA Conference and in the days since, we became aware of an increasing number of attendees who were not receiving emails through the conference registration and membership system called Wild Apricot.
After contact Wild Apricot, we learned that their system was sending out emails in one "format" but many email clients were expecting to receive the message in another format. For those email/IT folks, it is a TLS/SSL negotiation issue. As of now, Wild Apricot's development team is working on a solution.
The short-term "work-around" to receive emails is by configuring your email to accept email@example.com as a "safe sender." You can also pre-approve several IP addresses listed below.
The easiest solution is to visit https://gethelp.wildapricot.com/en/articles/63-email-whitelists and follow the instructions for your particular email provider.
Whitelisting SMTP servers: Here is a list of Wild Apricot IPs: