A common situation is the failure of eMails being sent from WordPress. Sets that can be take to resolve:
- If the webhost is separate from the domain and DNS MX records; add in the recommended SPF value to the DNS record.
- Use a SMTP plugin to directly login to the mail server for mail delivery
If the above does not work or cannot be configured, an mail relay host is the next resolution. SendGrid is one option for this configuration. Use the plugin POST SMTP and follow these directions from Kinsta: How To Configure SendGrid in WordPress With Post SMTP Plugin