Bookem doesn't support sending bulk email campaigns, but you can export your client list and use it in external apps like Mailchimp or SendGrid. The file you download will be in CSV (comma separated values) format, which most email platforms support.
External tools like Mailchimp usually detect and remove duplicates, so you don't need to worry if you import the same clients more than once.
You can export your client list in two ways:
Go to Clients
Click Export clients at the top of the page
Follow the prompt to download your CSV file
Go to your Calendar
Click the three-dot menu in the top right corner
Choose Download
When prompted, choose Spreadsheet (CSV)
Enter the date range you want
Click Download
You can now import this CSV file into your preferred email platform to send your campaign. The steps for importing vary depending on the tool you're using.