Hi Pam, About the email with no content...I wonder if John did write you, but what if someone else got a hold of it and deleted the content? If someone else accessed his email, they could have done it. Don't assume he did that. John wasn't that kind of person. Just think about it. He was an extremely considerate and caring person, especially when it came to YOU.
Personally, I believe those emails were from the real John. But you were so harrassed by Darby and the others it's a wonder that you even kept your sanity through it all. After all that you went through, don't feel guilty for doubting John. If you hadn't been crucified by the piranhas, you never would have doubted him at all.
About the email from John's mother saying "Dearest Pamela", well to me, that's an indication that she knew how dear you were to John's heart. So don't think anything suspicious about that, except that mother's know about these things. I have 3 grown sons, so I'm very experienced. Also, the mother of my true love knew all about me from her son. So regard Kay's opening greeting to you as confirmation that John cared dearly for you.
About you getting sick...sounds like that's from another you on another timeline that was created when you went time traveling with John and created an alternate timeline. Maybe when you had those dejavus or ran into someone who was closely related, it affected you physically, just like John was affected physically. Does that make sense?