Format preference for incoming mail changes to "Prefer MIME" and causes Active Mail to not fun (4251176)

When sending Active Mail the following warning is displayed in Notes

MIME Save Warning

The following items cannot be sent or saved in MIME (Internet Mail) format. Do you want to continue sending/saving this document?

When using Notes Migrator for Exchange (NME) to set forwarding for all new email to be delivered to Exchange, the "Format Preference for incoming mail" on the person document in Domino gets set to "Prefer MIME".  This will cause active mail not to function correctly as it requires this to be "Rich Text Format" as per the for Coexistence Manager for Notes Documentation.

Workaround

Run a second pass for Manage Mail Routing but this pass choose the following:

• On the screen "Specify Mail Routing Options" select Notes as the option under "All new mail for users in the collection will be delivered to", specify the other options as per the environment.
• One the next screen "Specify Exchange to Notes Mail Forwarding Settings" do not select any options an click next. 
• On the next screen "Specify Remove Notes Forwarding Settings" only select the option "Set format preference" and choose "Keep in senders' format" or "Prefers Notes Rich Text", then click next.
• Complete the remaining screens as normal.
   

Waiting for fix in a future release of Notes Migrator for Exchange