MX Lookup tool provides you information about all the MX records a domain has added in their DNS records. You have to enter a domain name and can quickly check if the email server of that domain is set up correctly and is or is not responding to the incoming emails. For every domain, MX records are compulsory if you want to use the custom email addresses for your domain. The email servers check the MX records of any server of any email domain before sending them an email, and if no MX record is present, then the email fails to send. This tool simplifies your work and checks if the email server is responding correctly or not. You don't need to send the email to the domain, and all you have to do is to enter the domain in the above-given field and check its email server availability.