Lync sends clipped text
I have the same issue with Lync 14.2.1 (150923) and El Capitan (10.11.2 (15C50)). It occurs only when sending messages to Lync for Windows (I'm not sure which version but one compatible with both Office 2010 and 2013). Mac to Mac messages look fine. The symptom is with line spacing (the vertical distance between lines of text) that causes text to be clipped and difficult to read.

I have done extensive testing to try to find the solution, by changing font sizes on both the sending side (Mac) and receiving side (Windows) to no avail. When I log in to my account on Lync 2010 (4.0.7577.4484) for Windows 7 through a Windows 7 VM, my messages look fine to recipients.

To conclude, Win-to-Win and Mac-to-Mac are fine, but Mac-to-Win is not, regardless of the font or font size selected on both ends.