At what resolution does the iPad email photos?

You can send your photos from the iPad at full resolution if you copy and paste them into an email. Otherwise, the iPad will reduce the resolution of your photos before emailing.

Depending on the aspect ratio and source of the photo the iPad Mail app will automatically reduce the size to 2048 x 1536 (4:3) or 2048 x 1364 (3:2) before sending the photos. This is approximately 3-megapixel resolution.