How can I send an invitation (jpg. ) as part of the email and not attachment?

Psst... I don't think you can

You can use a program designed for making invitations through e-mail. Specifically, E-vite. You can go and design everything you want on the invitation, put all the details, customize it for the event you want, and add all the e-mail addresses right there.

Either use an e-mail program which allows to insert photos into the body of e-mail, like outlook, or use photomail. http://photomail.mail.yahoo.com/ PhotoMail is email with photos inserted right into the text. The clickable thumbnail-sized images make it much easier to view and receive photos than getting them as attachments. PhotoMail is only available to those running Yahoo! Mail on a PC with Internet Explorer 5.5 or higher. Select photos from your own files, Yahoo! Photos, or Yahoo! Image Search. Drop them into your message. Then, if you want, resize and rotate the thumbnails and apply borders and captions. Each thumbnail is linked to the full-resolution photo, so that double-clicking on a thumbnail opens the big picture. Yahoo! Image Search thumbnails are linked to the web page where the image is posted. Double-clicking on them opens the web page. The full-resolution photos are accessible for 90 days to whoever receives them. Recipients can order prints, print at home, and play a slideshow. They can save the images to either their computer or to a Yahoo! Photos account—or both!