Hello @MistyT779 ,
If you're unable to compress your PDF smaller than 5MB, I'd advise finding other ways to reduce its size, such as splitting it into multiple PDF files (if it's a multiple page PDF), or seeing if you can use the original program to shrink the overall page size of the PDF.
Otherwise, the easiest solution would be to just host it on another cloud drive, use a 3rd party site to make a first page PNG (or PNGs of all the pages) to add to your email, and use the share URL from that in your email.
See also:
Text links
Image links
Button links
... View more