Kindly guide how to configure email server
what exactly are you trying to do? If it is about the mail server setup within SuiteCRM, have a look here:
Check your suitecrm.log file located at the root of crm. that will have more details about what is failing.
That looks like an old version. Since about 1,5 years ago that error message box has an additional link to a Full SMTP log which would give you more clues.