Technical difficulties - again?

I am the stand-in techie at my company. We are too small to have an IT department, or even one person on staff who is dedicated to computer related issues. So, it falls to me as I have the most knowledge about computers. I keep the web site going, fix software problems, monitor our mail server, etc. But when something goes wrong I feel like I am not equipped to deal with it. I don't know why the email suddenly stopped working at 8:36 pm last night! I have tried everything I can try, stop calling me! The phone is ringing off the hook with our employees in different locations calling in to find out why the mail doesn't work. Give me a chance to fix it people! Ugh. No wonder my eye is pulsing right now.