MNE is used to set forwarding on the Domino Person document. If the Person document is viewed, you can see that the proper forwarding changes were made by MNE. However, some users still receive email in Notes. It is only when the customer manually edits the Person document and saves it that Domino actually recognizes the new forwarding changes set by MNE.
This is an issue with corruption in the Domino Directory. IBM should be contacted to help with this issue.