I have never tried this and have no reason to at the moment, but maybe others will start to write something if you give more information? On the PC Amiga Forever seems to do all the hard work, as there is something called "Amiga Explorer" which as far as I understand works across a serial connection.
I havenĀ“t seen any macs with a real serial port for a while, so you probably own a serial/usb adapter and installed a matching .kext to get it going? You have tried Mac terminal software and the link is working OK?
Maybe you can get some info from the maintainer of the mac port of E-UAE?
my uaerc contains the following lines:
serial_on_demand=false
serial_hardware_ctsrts=true
serial_direct=false
uaeserial=false
HTH