Voicemail problem

can you please let me know about installing sip simple or presence software on asterisk 1.4.22 fedora server so that it can support IM plz any suggestion cz there must be some solution any idea about solving this problem and another problem is that two clients can receive and send voicemail but 1 cliant is unable to work i wonder whats the problem cz the all clients are configured from same dial plan and all settings are the same