Email Filtering Blocking Sales Insight Outlook Plug-In Invitations
Issue
Email filtering can prevent the delivery of the invitation email to the Sales Insight Outlook Plug-in, preventing end users from being able to activate the plug-in.
Solution
This can be remediated by white-listing the trusted IP range from the following document:
https://docs.marketo.com/display/public/DOCS/Setup+Steps#SetupSteps-AskITtoConfigureProtocols
The email invitation return path is determined by the Marketo user who is inviting in the instance. So if there is a restriction on the domain that the email can be sent from you can adjust this by creating a dummy user with a username with the a domain that would qualify for IT restrictions. Then log in as the dummy user and send the invitation. It will have the dummy address in the From line.