You can use Mail to email photos directly from Photos. When you use Mail to send photos in an email, Photos sends it from the first account listed in your Mail preferences. If you have other email accounts set up in Mail preferences, you can select which email account to send the email from when you send it.
Tip: If you have many files or large files to send, you can use Mail Drop to send them. You must have an iCloud account to use Mail Drop. You can use Mail Drop to send attachments up to 5 GB in size right from Mail on your Mac, or from icloud.com/mail on your Mac or PC. All file types are supported and attachments don’t count against your iCloud storage.
Select the photos you want to send.
You can send photos from your photo library or an album, but not from a slideshow or a project (such as a book, card, or calendar).
Click the Share button 
in the toolbar and choose Mail.
Mail opens a mail message with your photos attached.
Type the recipient’s email address in the To field, then type a subject line in the Subject field.
Type a message if you want, then click Send.