Searching for definitive constraints on iMessage video attachments. Through experimentation, it would appear that there is a file size limitation of around 25MB, although I have read accounts of 224MB being the limitation. There are many publications stating there is a 3:30 time limit on videos, but that is easily debunked. If sending an iMessage, while attaching a video from the message editor using the camera roll option, iMessage will prompt to trim the video attachment and then contrain the length to about 4:15 (in 720p 30fps). If I thry to send the same video (original length about 11 mins) from the camera roll using the share sheet (sharing to iMessage) it does nothing when the send button is pressed. Very frustrating to not be able to find any definitive doc on these contraints from Apple given the new iMessage app framework. Any insight greatly appreciated.