Getting "Please authenticate first" when trying to send a message via SMTP in Thunderbird #313

Trying to set up Hydroxide in Thunderbird and while I got IMAP working, SMTP does not seem to work. When I send a message, I get the message "Please authenticate first". My settings in Thunderbird are the following:

(in English)

Description: Hydroxide
Hostname: 127.0.0.1
Port: 1025
Connection security: None
Identification method: Password, transmitted insecurely
Username: thezipcreator

As far as I can tell, this is correct. However, when I try to send an email, the server responds with "Please authenticate first".

I'm not really sure how to solve it.