SMS mailbox full

This issue is presumably only present on older firmwares (notoriously on iOS 5, but also on 6-7 to some degree?).
When your sms.db grows over (presumably) 200 mb in size you’ll get the “Your SMS mailbox is full. New messages cannot be received until you delete some messages” error message upon entering Messages.app.
This is possibly associated with how iOS handles db files, not cleaning them when needed