Testing communication » Troubleshooting inbound
Problems associated with MX lookup
Whenever someone tries to send an email to a user in your company, their SMTP server does an MX lookup in the DNS to see where to send this message. If that server is not able to find an MX record it won't be able to deliver this email.
What is an MX record?
An MX record or Mail exchanger record is a type of resource record in the Domain Name System (DNS) specifying how Internet e-mail should be routed using the Simple Mail Transfer Protocol (SMTP). You MUST have an MX record in your DNS in order to receive incoming emails.
How do I check if my MX record is properly configured?
To see if the MX record is properly configured, run the Quick Test