I've had to deal with a number of problems with Macs clients and a Linux server so upon researching I've found so information that might be helpful to you. If you're running Mac OSX then you have the ability to turn on the capability of Windows File sharing. I've never tried it myself but apparently Mac OSX has the ability to run Samba. I'm posting the directions that I've found:
Setting up a Mac computer to share files with Windows users
You can set up your Mac so that you can share files with Windows computer users.
To allow Windows users to connect to your computer, you need to turn on Windows Sharing. When you turn on Windows Sharing, Mac OS X uses the Samba server software to provide SMB/CIFS file services.
You also need to give the Windows users the network address of your computer, and a user name and password of a user account on your computer.
Open System Preferences and click Sharing and, if necessary, click Services.
Select Windows Sharing in the list, then click Start.
Look below the services list for your computer's network address. Give this address to Windows users.
You can provide users with the user name and password of any account on your computer. To help keep your computer secure, you may want to create a special account for Windows users in Accounts preferences.
I think that if the Macs have the Windows file sharing turned on, a Linux computer can then access it just like it would access a Windows share. Essential turning on this feature on Mac OSX will trick Linux into thinking its communicating to a Window share.
I have not tried this myself since it was the solution to my problem. I hope this at least gives you a little idea about what to do. If the Macs are running OS 9 or anything lower than OSX, there's probably no way to access them from Linux. From all the research that I've already done, it seems that there isn't a way for Linux to talk to a Mac. Hopefully this idea about using Mac's Samba can be a possible solution.