Accounting error provides more information about QuickBooks Couldn't Connect to the Email Server . Go to the Edit menu of QuickBooks and choose. Go to the left pane and select Send Form. Go to My Preferences and choose the email account currently in use by you and click. Click on STMP Server Details section and fill in the server name and port to set it to your mail. If you not able to solve this, then call customer service - 1-855-481-5338.