I have been bemoaning the lack of spell check in Microsoft Lync since I first started using it (with the 2010 version). I was quickly disappointed when I discovered that, despite spell check’s omnipresence in all other things Microsoft, and most IM/Email/Communication tools, that it was missing from Lync. But no more!
You’ll need to have already gotten some prerequisite updates beforehand, then the Lync specific one, all of which you can find here: Description of the Lync 2013 update 15.0.4551.1005: November 7, 2013
Now Microsoft, how about offline message support (or at least an option to push the message right into email) next?