I still don't think this exists. In this day and age a Gigabyte for free is a really good deal. We won't get 1 terabyte free for a few years. You need a whole server to get 1 terabyte of space.
How much would a terabyte be? 100,000 gigabytes? Or 1000 gigabytes? Well, it sounds cool. >_>Who needs any more than like, 100 gigs anyways? My computer runs on 12 gigs. >_>;
What? If I had that much space, I don't think all my mail will ever fit that! Besides, why on earth would they need to have so much space for email? I mean, emails are just a few KBs or even Bytes? Only very busy people need that space! 0_o It's pretty obvious the people will exploit this feature and use it as a storage facility for their files. The world has gone wacko! (But hey, it's pretty useful too I guess...)
I signed up for an hriders.com account about a month or two ago. So far, it has not lived up to its 500 mB attachment claim in the least. Despite many attempts, I could not configure an SMTP account with my email client (Thunderbird), so I conclude that they do not offer SMTP. So the only option is trying to send attachments via their web interface. Even trying to attach a 5 mB attachment is iffy with that method. So if you're wanting to back up your mp3 collection, I would advice you to be prepared to send each mp3 individually.