The most common reasons for not being able to send emails through emil clients are wrong settings or blocked port 25 by the Internet Service provider.

Use the correct Mail Client settings:

• Incoming mail server (POP3/IMAP server): mail.yourdomain.com
• Outgoing mail server (SMTP server): mail.yourdomain.com
• Username: the full e-mail address like [email protected]
• SMTP authentication must be enabled for the login to be successful.

The most common mistake is to leave "My SMTP server requires authentication checkbox" unchecked. This option should always be enabled, since Khimaira-GreenEarthHost servers require such authentication. Below is a typical process for enabling SMTP authentication for your Outlook.  The actual steps will vary by email client.  Please check Help for your specific email client if this information is not workable for you.:

From the Tools menu select Accounts. The Internet Accounts box appears. Select the Mail tab. Your email account appears. Select the appropriate email account by clicking on its name and click the Properties button on the right. Then under the Outgoing Mail Server section check the box My server requires authentication. Do NOT check the box next to Log on using Secure Password Authentication.

Check connection to port 25

The standard port usually used for SMTP connection is port 25. Most often the reason for failed email sending is that your Internet service provider blocks this port. If this is the case we recommend that you use the alternative port 2525 for your email SMTP connection.