How do you know if your mobile phone supports pdu text format?

I have set up Microsoft Add in MOSA (Microsoft Outlook SMS Add-in) to my outlook and having issues using it. I connected a Blackberry Pearl to my PC and I get an error message (this modem does not support PDU format) when ever I try to send an sms. I have contacted Blackberry, my mobile network provider and Microsoft to explain this error but no one seems to know what PDU is or which mobile phones do support this so that I can use this add in. Also I am only moderately computer literate but any advice would be welcome!!!!