In some environments, Active Directory user objects may have multiple SMTP attributes. If these sync from Active Directory to Groupwise as contacts; this may cause NDRs if the Groupwise user selects to email to that non-existent SMTP in Groupwise environment.
1- Find the Connector Name
2- Right Click | Select Advanced Settings
3- Find Exchange to Groupwise Attribute mappings tab
4- Add the following:
5- Click OK
6- Save configuration
7- Restart CMG Directory Connector service