Question:

Why are the Event RSVP emails not creating Multichannel Activity records when using Approved Email with Events Management?

Answer: 

Events use the Multichannel_Message_vod records for establishing the RSVP actions, they are not used to create Multichannel_Activity_vod records. Multichannel Activity records are created when the Multichannel Message record is of the Approved_Email_Action_vod record type and not the Events_Management_Action_vod record type.

Related Documentation:

CRM Help Documentation:

• Tracking Multichannel Activities from Approved Emails
• Using Approved Email for Events Management