If you are a Blue Hosting client and your emails are not sending, please follow the below steps.
From other clients experience with Blue Host, this hosting has serveral specific mail requirements. For some clients making sure the sender email is registered with them. From a recent experience with another client at Blue Host, he had to Change the out-going port from 465 to 587. This can be done with a plugin called Postman SMTP Setup
The Outgoing Mail Server Hostname needs to be added here
Then you’ll have to add your email username/password. Finish the setup and try again the email with port 465 and port 587.