Question: how to send multiple photos via gmail on iphone?
Answer: First, go back to a photo album, tap the Edit button, then select the photos you want to send—say, a couple dozen or so.
Next, tap the Share button. ... 
Go to the Mail app, create a new message, then tap and hold in the body of the message until a pop-up menu appears; when it does, tap Paste.
Presto!