I tried to send a large scan (7.4 Mb) from Scanner Pro. I tried from inside Scanner Pro, and from the iCloud app. In both cases the mail ended up in the outbox, and could never be sent (no reason given). I had to go to my Mac (where the scan was donloaded to iCloud drive) and send it -- no problems. So much for the 'pro' in iPad 'pro.' Is this because a limit on attachment size?