[Dovecot] dovecot testinstallation does not tell how to quit

I am having problems logging in with RoundCube, so thought I should see if there were instructions for testing Dovecot login, and sure enough I found some at:

wiki.dovecot.org/Testinstallation

Well it works, so the problem is probably all RoundCube's, but this wiki page is missing an important line about how to end the Telnet session without killing Telnet! What is the quit/exit command? And please add this to the wiki!

Oh, I just guessed it:

a logout