Problem Sending Email on iMac

I'm sorry, I can't point you to a tutorial, but I may be able to help you. There are two things you can do. (1) To reset your settings (and passwords) you can usually visit the email provider's web site and obtain what you need there. Some will even offer tutorials on their web sites. Then carefully reenter the settings and passwords into the preferences section of your email app. (2) If that fails to work for some reason, then try creating a new account and going through the setup process. This varies by app, so all are not as friendly and easy as we would like. Then you can eliminate the old account. Also, and this is important, write down and store your settings and passwords for future reference, if and when needed. It never hurts to use the help information provided by your email app.