A member may Send messages to other members based on information about them. Request information about the members. At Mecca's core is a database of profiles, one per member. Each profile entry is a category name followed by values. The structure and needs of the group determine the set of available categories, how flexibly new categories can be added and how the values can be changed.
Members update their profiles at any time using a web-browser form or by sending a single message.
They can send mail to arbitrary classes of members, but can also centrally filter their mail to avoid unwanted mail and reduce network traffic. Here are a few examples. Individual members could selectively choose to get them based on content. Further in the future, good language translation might allow members to receive messages in the language of their choice. The translator program would all messages in one language, translate them and send them back to the system in a second language.