Auto dialer play mp3

I have four lines and I need to know how do I upload my own outgoing messages if in the mp3 format and how can I set it up where each line has a different out going message

You cannot play mp3 files directly for outbound calls. The reason is that the global standard format for telephone audio is: PCM 8 KHz, 16 bit, mono. All audio files must be converted to this format. For more information, please see Audio FAQ for Dialers

To play different message (audio file) for different campaign, simply run multiple BroadcastByPhone program, each with its own call list and message. When start broadcasting, specify the number of lines to be used for the campaign. It is recommended that the total number of lines among all campaigns is less or equal to the available lines of the gateway (in your case, it is 4 lines).