We have the host setting set with the same email address in both host email and SMTP User email and when tested it works fine. We can send test email to the host email and the users email using Outlook fine. When any user tries to get an email from the website like their registration or forgotten email they get a message Password could not be sent at this moment. Please try again later or contact the site administrator.

When we look at the event logs we see that the email is being rejected: Mailbox unavailable. The server response was: not local host xyz.com, not a gateway

For the like of me I am stumped, any suggestions to why emails are not being sent from the website?
 

I thought about that too but I have over 50 DNN websites that I am hosting and they all send email notices except for this one and they are configured the same except for the domain name.

mail.domain.com:25

basic

username

Password