Starting in May 2007 Yahoo! Mail will begin offering unlimited storage. From their announcement:
We’re psyched to be breaking new ground in the digital storage frontier by giving our users the freedom to never worry about deleting old messages again. And, like any responsible webmail service, we have anti-abuse limits in place to protect our users. BTW: As much as we’d like to just flip a switch and “unlimit” everyone on the same day, we’ll be rolling this out over a few months to facilitate a smooth transition — we know there’s virtually nothing more precious than your inbox.
- Yahoo Mail Announces Unlimited Storage, at TechCrunch