If you're trying to send a message through OSX Mac Mail, and you receive an error "Server not available", or you are simply unable to send an email. Follow the below instructions to ensure your email client is properly authenticating.
- Open Mac Mail.
- Click on the "Mail" menu.
- Select "Preferences".
- Ensure you're on the "Accounts" tab. (Be sure the account in question is selected in the left-hand list.)
- Under the "Account Information" tab, select the drop-down titled "Outgoing Mail Server (SMTP)".Close the "Preferences" window.
- From the drop-down, select "Edit SMTP Server List". (Be sure that the account in question is selected in the list.)
- Select the "Advanced" tab.
- Be sure "Authentication" is set to "Password".
- Be sure that "User Name" and "Password" are both properly filled out with your email account credentials.
- Click OK.
- Attempt to send a message.
