JoinMe dot com in Hong Kong is free, huge capacity, unlimited number of accounts, but I am unsure if they send your IP.

Go to Anonymiser dot com and they will sell you, cheaply, a package that ostensibly allows you to surf anonymously. Just remember to get an offshore account in one of the former communist countries; they are much less regulated, if at all.

Your best bet is to investigate the offers yourself; googling "secure" or "anonymous e-mail" is a good start.
Just remember that any domestic company may have compromised itself to comply with U.S. govt snooping regulations. Who knows what back-doors have been built in?

For example, domestic companies were, and likely still are, limited to 128-bit encryption, but foreign companies are exempt from that, which is why so many people use Pretty Good Privacy.

When it comes to your security and safety, don't be chauvinistic; some of the very best stuff is made overseas.

I just read an article on one of the tech sites, wherein they interviewed the biggest firewall and anti-virus companies, and some of them, such as Microsoft and McAfee, refused to comment on whether they alert their customers to govt-installed spyware. If I come across it again, I will post it for you