To configure your email account you must specify the following information:
Incoming mail server:
mail.domain.extension (Ex: mail.linuxgnu.com.ar)
Outgoing mail server:
mail.domain.extension (Ex: mail.linuxgnu.com.ar)
The pop3 username will be your account email address.
To configure sending emails (SMTP user), you must activate the box > "My server requires authentication" ;
then press the >"settings" button next to the authentication box, and check the option>"log in with"
There enter your data:
Username: [email protected] (Ex: info#linuxg.com)
You can see this username in the email account manager of your control panel:
https://cpanel.yourdomain.extension
Password: The password of this email account.