welcome to mailtester.com what is it? here you can enter an e-mail address to verify if it exists of if there are problems with it. a series of checks will be performed on the e-mail address but no actual e-mail is sent.
Email Server Test - Online SMTP diagnostics tool - MxToolbox
about smtp diagnostics. this test will connect to a mail server via smtp, perform a simple open relay test and verify the server has a reverse dns (ptr) record. it will also measure the response times for the mail server. if you don't know your mail server's address, start with a mx lookup.
Email Deliverability Tool - Check Your Deliverability
about email deliverability. this tool requires you to send a test message to mxtoolbox. our systems analyze the headers, the blacklist reputation of your outbound ip address, and your spf records to generate a comprehensive deliverability report.
email server test. ultratools email test provides real-time insight that is critical to understanding how your domains' mail servers are configured and available. this email test checks the domain for a valid mail server and responsiveness.