just curious not looking for reasons why it didn't happen, so please don't shoot me down , when I joined 5 months ago I winked someone (forgotten all about it lol)....had a response today
When we go "prospecting", lol, if a message is unread or unanswered after a week, we delete it and move on.
Having said that, we have had late responses, where people have been away for a couple of weeks, or have been unable to answer the mail due to some reason or other.