Looking for logging into the Mailserver Test site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Mailserver Test site. After that you can login as usual with your login credentials.
https://www.smtper.net/
https://www.ndchost.com/wiki/mail/test-smtp-auth-telnet
https://pingability.com/smtptest.jsp
https://www.dotcom-tools.com/email-server-test.aspx
https://www.thomas-krenn.com/de/wiki/TCP_Port_25_(smtp)_Zugriff_mit_telnet_%C3%BCberpr%C3%BCfen
https://www.ultratools.com/tools/emailTest
https://www.checkdomain.de/webmail/
https://www.dnsstuff.com/mstc
http://mailtester.com/
https://mailtrap.io/
https://wiki.ubuntuusers.de/Mailserver_testen/
https://litmus.com/email-testing
https://docs.microsoft.com/de-de/exchange/mail-flow/test-smtp-with-telnet