Q: how to send a large PDF

Don't use email, most personal email accounts prevent file sizes over 2 MB,  instead use a file transfer service, I use Dropbox which completely Mac compatible.

Yes, any file can be transferred using Dropbox.

Apple has a great solution for what you're looking for - may have been a more appropriate suggestion since we're in an Apple Forum..

iCloud: Set up an @icloud.com email address

Mail Drop limits - Apple Support

Dropbox is an ok solution, but with MailDrop, there is much less work for the recipient of the file/email.

Hope these resources help you out. Good luck!

I use Google.. Gmail has 25MB limit per message while most ISP's are limited (at least mine is) to 5MB. Serves me well.