I haven't been able to determine a definitive / outstanding service that lets you test your site in several versions of IE on a mac (now that IE is discontinued)... how do people usually do this?
The actual IE for Mac has died long ago and was barely related to IE for Windows anyway. If you mean current versions, try something like Saucelabs interactive sessions. They offer many different OS/browser combinations in VMs and even their free offering is plenty for light use. <a href="https://www.saucelabs.com/" rel="nofollow">https://www.saucelabs.com/</a> for more...<p>In more limited form, Microsoft have their own freely downloadable VMs for certain versions of IE, though there are some tricky licensing issues, the VMs expire, and it's all quite cumbersome. <a href="http://www.microsoft.com/downloads/en/details.aspx?FamilyId=21EABB90-958F-4B64-B5F1-73D0A413C8EF" rel="nofollow">http://www.microsoft.com/downloads/en/details.aspx?FamilyId=...</a><p>For really basic tests, there's also the IE net renderer at <a href="http://ipinfo.info/netrenderer/" rel="nofollow">http://ipinfo.info/netrenderer/</a>
If you're looking for a service, Browser Stack (<a href="http://www.browserstack.com/" rel="nofollow">http://www.browserstack.com/</a>) gets the job done.<p>Microsoft also offers free VMs for testing IE at modern.ie (<a href="http://www.modern.ie/en-us/virtualization-tools" rel="nofollow">http://www.modern.ie/en-us/virtualization-tools</a>) for Virtualbox, Parallels, and VMWare. They have 9 or so images for testing IE, ranging from IE6 on Windows XP, to IE11 on Windows 8.1.
We run <a href="http://testingbot.com" rel="nofollow">http://testingbot.com</a> which provides just that: online browser testing. In your case, just go to our website, sign up for a free account and run any IE/Firefox/Chrome version straight from your mac. Please let me know what you think, we appreciate any feedback!