Thanks for the additional replies.
I am not sure if there is a DTMF Card in the system. All I know is that my technician originally told me there were 4 analog (SLT) ports available and that we could use two of them for voice mail. I had a program manual and saw references to voice mail so I just figured it would work. We needed to order the customer a 20 button phone so that we could finish the programming (they only had 2010SD phones) so as soon as I get it we'll be driving back to the site to finish up....man I hope I don't have to tell them they have to buy another card after surprizing them with the news they needed to buy a phone just so we could finish programming. I only agreed to do this because they are looking at putting in a completely new system at another business so I'm trying to get my foot in the door with them. I should have probably stayed away from this....oh well, live and learn !