At work I'm running a monthly process and the production staff asks "Is it ok to start the process?" I wanted them to start it an hour later but figure they may as well start it now, so I respond "OK."
A co-worker sees the email and tells the production staff "Don't run process, as there is a problem with the data."
I check my emails and find an email that I miss that states about the data error. The moral of the story is to be up on emails before responding.
I'm waiting for a user to respond to a question I have so I send them the question again saying, "I didn't see a response to this..." One good thing is I didn't email "You didn't respond to me ...."
It turns out the user sent a response the previous night and I didn't see the email. Email sucks. The user was pretty pissed. But this happened because I get so many emails from distribution lists that I wind up missing some important ones.