Below will show you how you can enable SMTP authentication for Microsoft Outlook 2013 :
Microsoft Office 2013
1. Launch Microsoft Office 2013.
2. Click "File".
3. Click "Info" from the left side menu.
4. Select the Account Settings.
5. Double click on the email account that you wish to set for.
6. Click "More Settings".
7. Select the "Outgoing Server" tab.
8. Select "My outgoing mail sever (SMTP) requires authentication" and Use same settings as incoming mail server.
9. Click OK.