For reference, I included the info on the copy/paste operation. The clipboard has always been a part of the copy/paste process, it just usually is unseen by the user other than the message you saw verifying that the data was copied. It may be that images in your email are not copied. Does it show all the content as being selected when you choose copy?
Select, cut, copy, and paste text on iPhone – Apple Support (UK)
Depending on where you want to paste the information, you may have better luck using this method.
- Tap the Forward button on the bottom of the email (looks like a backwards arrow)
- Scroll down and select Print.
- Tap the Share button on top of the screen (looks like a square with arrow pointing up)
- Then you have a couple of options. You can choose the Copy option and paste it like you normally would or choose one of the apps you want to paste it to.
This method copies the entire email as a pdf and includes all information in the email, so you do not have the ability to choose only part of the email to copy.