After installing the server, how can I add a username and password?
Do I need to install additional software to create a username and password? I can't seem to find them.
I keep receiving a message that IMAP connection is failing.
Roundcube - its just web-based maill client.
So you must install IMAP, SMTP server and create on it users accounts.
Hello, are you asking for recommended IMAP and SMTP servers? Some popular options include Kolab, Mail-in-a-Box, iRedMail, and Mailcow.
No - I answer to your question about creating new login.
Creating new user login depend from your server. You can store users in Database, OS, LDAP, AD and etc.