Verify that email address is the same in USS and SDM.
1) Log into Service Desk Manager > Administration > Security and Role Management > Contacts > Search for the user > Verify the email address set and configure if necessary.
2) Log into Unified Self-Service with the same userid > Select the dropdown arrow in the top right corner > My Profile > Edit my Profile > Verify the email address set. If you need to configure the mail address in USS, then do the following:
Log into the USS Control Panel as an administrator (example: CASMAdmin)
In the left hand pane navigate to Portal > Users and Organizations > Search for the User with the incorrect email address, modify accordingly and Save.