This trick can be used for diagnosing your email connection issues. There are more complicated featurees can be typed but are not covered here.

The following commands need to be typed in exactly and then followed by pressing the return key. Yhe session will not handle deletions, if you perform a deletions you will need to start again.

telnet testserver-com.mail.eo.outlook.com 25
ehlo testserver.com
mail from: bob@builder.co.uk
rcpt to: info@testserver.com