Sending large numbers of picture messages will get your number flagged by carriers. We initially removed the MMS feature for groups but now you can send pics for groups less than 150. For larger groups, you can use a URL. You can still send and receive unlimited pictures when engaging a specific person.
You can also send additional file types like PDFs, PPTs, MMS, DOC, DOCS, etc. Some of these may be converted into a link that will direct them to that file. There is a max of 2 attachments / uploads per message sent.
We recommend using a short code to send picture messages to groups. Learn more about that HERE.
Picture messages are 2 credits per picture, per person.