VTEXT.com works great for SMS. For MMS (pix, video, groups) use VPIX.com. The format is the same 'firstname.lastname@example.org'
Give that a test and see if everyone is able to receive your message.
Thank you for your answer, however, vpix.com does not come up as an active website for me. It just says website not available. And I am not sure what you mean by the email format. For vtext i just go to the website "www.vtext.com" and use it on my desktop directly.