Communication is repetition.
Use different communication platforms, and frequencies to make the message stick. Next to formal announcements by mail, organize monthly exchange calls with a variety of topics and speakers. Use small multi functional coffee chats (both in person and online – max 7 participants). Share a bi-weekly newsletter.
Everyone has a different way of absorbing information, some need a dialogue through e.g. a coffee chat, others need to read the message in their own time – which a newsletter addresses. Do not be shy of words, following Jeff Bezos’ memo principles make sure to go into enough detail and explanation to make everyone understand the state of the business, and the direction we’re going.