You most certainly do not want to provide someone an email sent to you, with the tracked links attributing all Email and Web activities to your lead! That would be catastrophic for reporting.
If you set all links in the email to untracked, that would at least be a reasonable starting point. It's infinitely better to have anonymous traffic than misattributed traffic.
It's also possible to have a 3rd-party sender generate link that are associated with individual Marketo leads. Provide them with the Marketo Unique Code of each of your recipients and ensure that the LP(s) you link to have pURLs enabled. You'll also want my pURL fixup JS on those pages. In this case you still don't want the email to contain Marketo's typical rewritten tracked links, so tracking must still be off. But you have them append the Marketo Unique Code to the URLs, i.e. pages.example.com/landingpage/{Marketo Unique Code} → pages.example.com/landingpage/ABC123.