An inhouse EP instance could show the following Error message:

EasyProjects.Templates.NotificationException: There was an error sending a notification message. See inner exception for details ---> EasyProjects.Templates.NotificationException: There was an error sending a notification message. See inner exception for details ---> System.Web.HttpException: Could not access 'CDO.Message' object. ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Runtime.InteropServices.COMException (0x8004020F): 550 5.7.1 Unable to relay for user@email.server.com

"Unable to relay for user@email.server.com" text in the details of the error means that you should use SMTP Authentication for sending e-mail through your e-mail server.

Please perform the following actions:

Log in as Administrator, open user menu - Settings - Notifications page, go to 'Email sending settings' area.

1. Check the box 'Use SMTP authentication'.
2. Enter an e-mail account name which exists in your SMTP server to the 'Username' field.
3. Enter a password for specified SMTP account to both 'Password' and 'Confirm password' fields.