There are 3 methods for sending a message to a Listbox list.
All accounts have access to the Message Composer. If you would like to be able to send a message from your favorite email program, please go to Settings->About This List, and make sure that "How will messages be sent to the list?" is set to either "Administrators can send email" (for email marketing campaigns) or "All Subscribers can send email" (for discussion listserves).
Check out our video screencasts on sending a message:
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