Apple - iOS reply to email with attachment
The easiest way to add a photo as an attachment is to open you photo library while multi-tasking find the photo you want to attach.
Hold down on the image until the copy button appears, Hit copy.
Go back to Mail and hold down in the body of the message. Hit paste when the option shows up.
Repeat until you have all the attachments you wanted.
Its also possible to attach multiple photos at once. To do so (applies to iOS 8.1.1):
- Switch to the "Photos" app and tap "Select" button in the upper right corner
- Select photos you wish to attach
- Tap "Share" button in the left bottom corner (box with an arrow pointing outwards) and choose "Copy"
- Switch to the "Mail" app, click "Reply" and hold in the body of the message until the pop-up menu appears.
- Choose "Paste"