In dreams, receiving or sending a message highlights the importance of information per se. Particularly if we work in the creative fields and information technology, messages in dreams will represent our ability to handle such input.
To remember the input suggests the information is useful, to forget, that we have the information but must rediscover it.
A message in a bottle signifies that contact is being made from the less accessible parts of our personality. Consult the entries for bottle, communication, email, letter and parcel / package for further clarification.