Microsoft Office 365 / Outlook For clients using these email services, the email account will usually send the form notifications to the Junk Folder, and eventually block. Therefore, it is important to liaise with the client to add the relevant Allowed or Safe Senders...
mailgun
Mailgun domain setup and configuration
If you use the Mailgun account, please request a user account. (Mailgun account security has changed and MakeWeb requires users to activate 2FA, in order to avoid breaches that can affect every website using Mailgun.) 1) Create Mailgun Domain & Configure DNS A....
Does the nameserver point to MakeWeb server?
https://www.whatsmydns.net/
Is this website hosted by MakeWeb?
IP Addresses for MakeWeb Servers: 103.127.163.168 (newest server) 103.127.163.167 (newest server) 101.0.102.238 (newer Digital Pacific server) 101.0.80.106 (old server)
Do the MX records indicate that they are using their own G Suite account?
https://www.whatsmydns.net/