RUMLog by DL2RUM
[ website ]

"RUMlog is a short-wave logging and QSL handling/printing tool for Mac OSX. In version 3 RUMlog was completely rewritten and is a Universal Binary now.
The logbook of the world is full supported, you can get different statistics for paper QSls. It’s just a mouse click to upload or download new QSLs to/from the ARRL server.
It is a very simple terminal integrated. It is useful for PR connection to a DX-cluster. Or just use it to monitor the local digipeater for DX-announcements. RUMlog will separate DX-spots and alert you when there is a "new one". Or you can use the Telnet function to connect an Internet DX-cluster everywhere you want.
RUMlog is available with an interface for transceiver control. Supporting Kenwood, Elecraft and ICOM. (IC-7400/IC746PRO, IC-7000 and IC-706).
A documentation file is included in the package."
There are no SWL logging fields in this logbook, so you can use the "Note" field to write down correspondent callsign. If you need to upload your log to eQSL I've write a tool that convert adif file generated by RUMLog in eQSL adif with swl correspondent field support.
[Download adif converter]

There are others logging software made for Mac. I've found that RUMLog is clean, fast, full of utilities and... free!