Cannot add pop3 account

[gastonhks]

Hello, install this great software, I would only miss one thing to finish my tests.
add an external pop3 account.
login session with a test user, and when adding a pop3 account I receive this error
pop31.jpg
pop32.jpg
pop33.jpg

if I use imap instead of pop3 it works.
I would be missing some configuration to enable?
I appreciate your response, thank you very much.