It is a scam. Do you really think PayPal would forget to put, or omit, links in their emails?
This PayPal page might be particulary helpful ("How to Spot Fake Emails"):
https://www.paypal.com/selfhelp/article/FAQ2340/3
(If that link doesn't work, open the Help section in your PayPal account and search the word "scams".)
One of the things the page says is: "The email says the money is “on hold” until you complete an action (i.e., send money through Western Union or click a link to submit a tracking number). You can easily see if you received money by logging in to your PayPal account (do not click any links within the email). If you’ve been paid, you’ll see the payment in your account."
These sites, too, have whole sections on fake emails -- and, specifically, on "Nigerian Scams", as I recall:
----- Search for Scams here: www.fbi.gov
----- And, here (Internet Crimes): https://www.ic3.gov/crimeschemes.aspx
(If neither of those links work, search for "Internet crimes" and the like, on the Net. Go to Government (.gov) sites for the most reliable info.)
Your PayPal account should, also, have info reguarding the "on hold" or "pending" transaction, as well. Does it? (Go directly to your account, NOT through any email link, etc., to check.)
Sad, but true -- it is a fake email. 😞
