It depends on how you were getting your mail. If you were using Outlook and storing the emails on your computer, then you have to put back in all the setttings, user name, password, etc..for your email in Outlook.
Or a better way, just go directly to the web site of your email provider and login, this way it doesn't junk up your computer and all the mail is secure on their cloud, ready and available for you to access from any device, in any location.
I preferr Gmail. Just go to gmail.com if you had a Gmail account. If you had an exede.net account, go to my.exede.net and login, then click on the Email link in the left corner.
Hope this helps! But seriously look at a cloud based system, it will keep this from ever happening again because it is accessed through a browser and not an application that way you never loose anything.