OK, so you are not "using the latest version of everything": in your context, the latest version should be something like PersonalEffect (uProduce / uCreate) 13.1.1, XMPL 3.5 and XES 3.7.
In my knownledge, on-the-shelf, it is not possible to attach an XMPie personalized PDF to an XMPie personalized Email: the only thing you can do is to add a personalized Link to an XMPie email, that will trigger the composition of an On-Demand PDF, based on an InDesign (or XLIM) document template.
The easiest way to implement this in an email is certainly to tag the email body with the PDF Touchpoint taken from the "Special ADORs" tab in the left pane:
The related XMPL code should look like this:
Then, if your problem is still alive, you may wonder, what is the URL generated by the Link, and if there is any obvious or non-obvious reason for that.
In my case, the URL composed by the XMPL code in the Email looks like this:
If you think your situation is a bug, feel free to contact the XMPie Support Team.