Message retention period

Currently, if you want to maintain a low digital footprint, you need to regularly go through and purge your messages, however, doing this clears out everything, making even recent messages disappear completely.

The option to have a retention period, or TTL on messages, set as an account default, and the ability to customize by community, DM, group chat, or channel, would give people greater control over their message history, allowing chats to automatically be cleared out after a set period. I could see communities also being able to set retention periods on their channels, with the server processing it based on the lower retention period defined by community and user. To reduce server load, you could probably have it be processed daily, rather than needing to constantly be checking every message against it's retention period.