Forwarding messages to a new identity
psyced has the ability of forwarding messages to you from an old account to your newer account. You can activate it by issuing /set id <uniform> where <uniform> is your new psyc://something/~you identification address that you figure out by watching your own profile (/x or /surf commands).
Setting your identity actually instructs your old UNI that it is no longer in charge of your identity...
See also: redirect.
Forwarding from your identity to a client
Perfect forward secrecy
See Encryption for that.