If a PDF is too large to be sent via email the file size may be reduced, as long as its layers haven't previously been compressed.
Open the large PDF file in a pdf viewer:
1) Click File
2) Click Print
3) Change Printer to "print to PDF"
4) Click Print
5) Choose a save Location
6) Name the File to be reduced
7) Click Save
- After the save is complete, attach the newly created file to an email
NOTE: if you notice that the file is the same size or larger than the original, then the original file was already compressed.