If you're going to email people, you're going to run into attachment size limits. It's a fact. You might not have noticed, but email client Thunderbird makes it nice and easy to convert attachments into Dropbox, Box.net and other cloud storage links.
Filelink, as Thunderbird's cloud-attachment feature is named, has been around since version 13, but perhaps little noticed in light of Thunderbird's slowed development. Even if Thunderbird isn't your main mail system, having the ability to crack it open, point to a file, and let Thunderbird take care of uploading and linking the file while you do other work is pretty handy.
Filelink only works for outgoing mail, although dragging attachments into Dropbox or another service isn't too hard for most of us (and attachments won't come through, anyway, if they're too large for your server).
Filelink is included with the latest versions of Thunderbird (Version 16 is out today). Only one or two storage services are included by default, but you can add Dropbox and other clients through add-ons.