Two main ones – one for personal email, one for work email. I can’t access the work account from anywhere outside the corporate intranet, and I’m not allowed to go to personal email while I’m at work (so I just have my personal account auto-forward to my work account).
I have three accounts with my former college/employer – one main one that is nothing but spam so I never check it, one from the department I worked for and graduated from, and one alumni account that I just have auto-forward to my main personal account.
I have one account with Yahoo from wayyyyy back in the day, that I haven’t checked in about 10 years, and use only because it’s linked to my Flickr account.
I also have an account I use for sites I expect to spam me when I sign up, and I check it once a month (also the account I use for posting on Usenet)
I have another account for things that I know are going to spam me, that I never check.
You can also email me via my phone number @ my wireless provider, and I’ll get it as a text message.
I also have an address on my Wii that you could use to send me messages I’d receive on the Wii.
So I think that’s a total of 10.