So far in September you've sent 776 messages so it's likely that you will be impacted by this. To send more than 500 messages a month, please upgrade to MightyText Pro. Starting in October, users of our MightyText free version can send up to 500 messages per month.
Since you're one of our most active users, we wanted to tell you about an important change in MightyText coming in October. I'm not sure how to check how many messages you've sent through MightyText though. I think I only got the email because I would be over the limit (currently using >500 messages a month), so maybe you weren't likely to be affected.
