Our engineers identified an issue with the SendGrid notification system which caused erroneous email credit notification alerts to be sent out to subset of customers for the month of July. As a result, some SendGrid customers may have incorrectly received a notice from SendGrid with subject line "SendGrid Email Limit Warning". In the event that your account's sending is not near or at its usage limit, this notification was triggered due to a system notification failure and not as a result of reaching the account's email credit usage limit. A fix has since been deployed and the system is now functioning as expected.
If having received this notice, please review your account's July usage to determine if you are nearing your account usage limit. You may find your credit usage within your SendGrid parent account by navigating to "Settings > Account Details > Your Products". This incident did not affect the mail send for customer accounts.