I was supposed to meet someone last week for a coffee. This was an introduction that was me doing someone a favor. But they never showed up and I only just now (Monday morning) got an email of apology and explanation. It was not super detailed (i.e. it didn't say she had been in the ER or anything drastic) and now they want to reschedule. I am pretty miffed and want to ignore the email. Is that unprofessional? I mean we obviously have a connection in common but I feel like I don't owe this person anything now. In general, how do you deal with work meetings where you are stood up?