Hello, is there an upper limit to the plug-in (i.e. 500 emails in a batch)? If so, can it be configured for > 500?
Hello @gbobrek, 
Thank you for your question. Please note that the batch endpoint accepts up to 500 messages per API call, with a maximum payload size of 50 MB, including attachments. If you need to send more than 500 emails, you can do so by using multiple actions in your workflow.
For example:
- Action 1: Send the first batch of 500 emails.
- Action 2: Send the next batch of 250 emails (or however many additional emails you need to send).
This approach allows you to send more than 500 emails by breaking them into manageable batches.
If you have any further questions or need assistance, please feel free to reach out.
Best regards,
Daniel