How to send large hd videos by email?

If the quality is bad that means your original file is bad. Uploading to or downloading from Dropbox will not alter the image quality. If you insist on trying to email the file you could cut the file into multiple pieces and send them one at a time. For a 49 meg file I would go for 20 pieces. Be sure to include instructions on how to put the pieces back together again so they can watch the video.

You can try sending it through Gmail. Attach the file like you normally would. If it's too big, it will tell you to upload it to Google Drive. Once it is uploaded you can attach the file to the email using Google Drive.

Hope this helps!