This applies to users who have their domain hosted through GoDaddy and an Office365 account purchased through Microsoft directly.If you want SMTP integration to work properly, follow the screenshots below.I am using osTicket 1.10 and PHP 7.0 hosted through GoDaddyAt a high levelGodaddy - Select Remote Mail Exchange and list your domainosTicket - enter localhost (GoDaddy) for hostname Exchange - Enable SMTP relay from your Godaddy hosted server IP addressFollow the steps in this link starting from this sentence https://www.netwoven.com/2015/12/24/smtp-relay-for-office-365exchange-online/"In the Exchange Admin Center, select Mail Flow > Connectors.

"Check your SPAM folder if you are not receiving messages