you can go into the pictures app, click the little swish arrow in the top right.
select the multiple pictures you want, click share, and hit email.
You can send a certain number of pictures, i think somewhere i got was around 6 pictures a single email, there seems to be some sort of limit. You can do this same method for MMS too, although there is a limit on that too.
EDIT: checked it real quick. The email option goes away after i select 6 pictures (so 5 pictures an email) and the message option goes away after i select 10 pictures (so 9 pictures per message)