Mailing a letter is still very cheap in China. Until today mailing a local letter set you back only RMB 0.6 RMB (EUR 0.06) and a nationwide letter just RMB 0.8. But it seems China Post is not making enough money, because as of today they have increased their prices. And not just by 1 or 2%: local mails go up 33% and the price for nationwide letters increasing by a whopping 50%!
I hope China Post’s service will also get a bit better, but I fear this is wishful thinking. Anyway, I never use the quite unreliable mail service, except for receiving letters and packages from abroad that have been opened. When I need to send something I either use a courier, so you know for sure your letter or package will arrive (without being opened), or otherwise I use good old free email.