Yes, it's good to have that many messages allowed so you don't have to clear your inbox all the times
wow, that's plenty. I have hundreds of IM friends but I'm unsure is I need that many space for messages.
Sadly, messages are automatically deleted after 90 days (for free members) and 180 days (for premium members).
Digital Point has a feature that automatically delete emails older than 90 days. Its great because you don't need to do it manually.