All_Dawson is used to send official messages to all employees. It is typically used by secretaries or managers for notifications of academic events, interruptions of services, etc. Employees cannot opt out of this distribution list.
Only managers and their secretaries may send to firstname.lastname@example.org. Try to have the content as text in the body of the message, as opposed to an attachment. If you do have a document to attach, make it PDF, and still include in the body enough information for people to know what it’s about. Do not rely on special fonts, colours, etc. to “add meaning” to your message.