Sip Client for Windows Mobile 2006?

hi all,

i just bought an HTC s710, should be delivered in the next couple of days..
i'm wondering if it has a built in SIP managing settings! as in if it could be used as a sip phone so to speak!

or should i look for a seperate sip client to install!

ps: any info would be appreciated:)

ps#2: if theres no sip option on this wm6 do u know of any sip client tht would be free and simple to use!

thanks in advance:)