Hello, please tell me where can i get a free email,for undernet.org.
I tried so many different sites, but they are not good.
Thanks.

Use your ISP's email? Or, create an extra email through your ISP (many allow that for no extra cost) if you want a "spam" email account.

Other than that, Google around. There are a variety that are free, but Undernet and other networks often block the more common free email sites because they are commonly used by hackers, spammers, bots, etc. Gmail is notorious for spammers, for example.