Gazelle's reminders are primarily a 'Drip Marketing' and 'Event based' automated messaging system and is not designed as a mass emailing / newsletter system. For newsletters or mass emailing clients we recommend using MailChimp or other similar products that are uniquely designed for sending out newsletters and other bulk messages. MailChimp even has free account options if you have less than 2000 customers. You can export your contact list from Gazelle by following these instructions.
What is 'drip marketing' / 'event based' vs. 'mass marketing' system?
Drip marketing (or event based marketing) is an automated message system that sends pre-written scheduled messages to leads & customers over time as they meet certain criteria (e.g. a piano coming due for service or an appointment that needs to be confirmed). Mass marketing blasts everyone today,
Can I create a workaround where I set up my 'drip marketing campaign' to act like a 'mass email system' to announce something to my customers?
You can use the first message in a 'Drip Marketing' campaign to message everyone (which is what we recommend when you first start using Gazelle reminders). However, stopping and restarting a drip marketing campaign to utilize the first message as a mass marketing tool creates a lot of unnecessary work, provides unreliable results, often has unintended side effects, and is overall not recommended. Using a product like MailChimp will save you time, provide better results, and has a greater chance of meeting your needs.