Looking for logging into the Telnet Smtp 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 Telnet Smtp site. After that you can login as usual with your login credentials.
https://qiita.com/azumakuniyuki/items/99c341e99a459d6214bc
https://blog.janjan.net/2018/03/07/smtp-auth-telnet-login/
https://www.ndchost.com/wiki/mail/test-smtp-auth-telnet
http://takuya-1st.hatenablog.jp/entry/2015/03/12/192435
https://hogem.hatenablog.com/entry/20100121/1264179124
https://centossrv.com/memo/log/18.shtml
http://www.serverhacks.net/mailserver/smtp_authtelnet/
https://help.atmail.com/hc/en-us/articles/201608574-Testing-SMTP-AUTH-using-telnet
http://www.tohoho-web.com/ex/draft/smtp-auth.htm
http://d.hatena.ne.jp/toshi_hirasawa/20111124/1322134634
http://ash.jp/net/telnet_smtp.htm
https://docs.microsoft.com/ja-jp/exchange/mail-flow/test-smtp-with-telnet
http://blog.torigoya.net/2012/02/19/telnet-smtp-auth/