embedding a LinkedIn Profile in signature on email

I recently got a new Macbook Air. (My previous MacBook was lost, so I could not just transfer everything over.). I added my email accounts to the new computer, but when I tried to use my email (gmail and other) I saw that my signature block had disappeared. on all email accounts. When I tried to recreate the signature blocks, I could not embed a link to my LinkedIn profile that had previously existed on gmail. What happened and how can I fix this?