As all the other posters have already mentioned, your plan won't work. But way back when anon.penet.fi was finally forced to reveal through the legal system, the real email address of a user, I did a bit of a mental exercise.
How could someone create a pseudonymous remailer that would be extremely hard if not impossible to break through the legal system?
The scheme I thought up was as follows.
1. Maintain an encrypted database of email addresses and pseudonyms.
2. Have the key to the above mentioned database stored only in RAM and never written to any persistent storage.
The above scheme would work, but power failures and reboots would effectively destroy the database so it's not a complete solution. But to work around the power issues, add the following.
3. A UPS to minimize power issues (not really required, but will reduce the down time)
4. Have the key split into multiple parts and have those parts sent to multiple trusted parties in multiple legal jurisdictions. There's plenty of secret splitting techniques out there to do this. And if your escrow parties happen to be in the USA, Finland, Italy, Switzerland, etc., it would be rather difficult to have enough of them divulge the key portion that they've been entrusted with. And of course, have those parties instructed to destroy their key portion if they ever discover that legal proceedings have been engaged against you. And of course, have your lawyer instructed to inform those parties as well.
So in the above situation if you lose power, or need to reboot, the system will be in an unusable state, but will contact the escrow parties to retrieve the key parts and reconstruct the encryption key. Once this happens, it resumes normal operation. But most other governmental attacks would have a very slight chance of success.
Of course, other refinements could be added such as a periodic "ping" to the escrows informing them that things are still OK. If a sufficiently long time elapses without such a keep alive ping being received, the escrow would delete the key portion entrusted to it.
To break such a system would be extremely difficult.