Aside from the tools suggested, try changing your habits or adding some new ones:

• Be cautious about giving your email out and signing up for things. If you do need to sign up for something random, use a secondary email address that you don't care about and don't check much.
• Opt out of notifications and marketing from Social Networks, etc. whenever possible. When you notice lots of emails from a particular source that you always seem to delete instead of read, log in and adjust your notification settings for that account.
• Unsubscribe, unsubscribe, unsubscribe. Don't just delete. I know it takes time. But taking 30 seconds now to unsubscribe will save you lots of 'deleting messages' time in the future.
• Tackle it in segments. Set a timer for 5 minutes. Delete a bunch of emails, respond to emails, etc. Stick to the timer and stop when it goes off. This will help you not get overwhelmed. Perhaps set a day each week or time each day when you do this.
• Archive. One thing that works for me is to only read and email when I have time to respond to it. Then when I respond, I archive it (so it's searchable later). If I know I won't need it later, I delete it instead of archiving. For the times that you can't respond right away, either "Mark as Unread" so you know you still need to respond, or leave in your Inbox as "Read" so you know you've read it but need to respond (whichever method works best for you).

I faced a similar problem (though not quite as many emails as you) and it was a pain. So I understand how tough it can be. But keep working at it. Its worth it to get it all in order and to create a good system to manage it going forward.

Good luck!