Can a Sales member send an email to multiple people using the MKTO plug in?
I ask this because as far as I know Marketo Sales Insight for Salesforce only lets you send an email to one lead at a time, correct?
Marketo has some documentation that will help answer your question, but in short: "If you Send and Track an email with multiple recipients, Marketo will log all click and open activities to the first recipient in the To... field. Activity done by other email recipients will appear in the first recipient's activity log."
Basically, sending to multiple recipients doesn't do what you're trying to accomplish. YES you can physically send the email to multiple recipients, but only the FIRST recipient on the list will get the Marketo activity associated with sends/delivers/opens/clicks, and those activities will be the actions of ALL recipients, not just the first on the list. Not too pretty.
However, bulk-sending actions are possible in SFDC. It's built-in functionality for SFDC Classic, but not Lightning. However, there's another thread with more information on how your SFDC admins can help get the bulk send enabled in Lightning, but it does require some work.
Just circling back on your post! If my response helped to answer your question, please feel free to mark it as correct so that the thread shows up as 'resolved' in the community.