I was writing an email today, and I was supposed to write a phrase like this "did it for all of 'em", even though I eventually changed it to them as them as that looked a little informal to me, I am not rally sure if this is what the case is?
and just for information, mail was not for any boss/manager, it was just for a colleague but she is in US and I am not so I didn't know whether it is okay or not?