Calling on my Salesforce wizards out there
My Salesforce admin reached out to me yesterday to let me know they are vetting a SFDC encryption tool called SF Shield and wanted to know if I had any idea how this might interfere with our Marketo integration. I have no idea, but I am hoping someone else does. It will selectively encrypt emails, notes and attachments.
If this is restricted to emails, notes and attachements, you have no issue: these elements do not sync with Marketo.
Just check that it will not encrypt any field value in lead, account, contact, opportunity or activity (task / event) objects as well as any custom SFDC object you may have mapped.