Having been through quite a few different ISPs through out the last 6 years, I had to have an email provider that I could constantly use without having to worry about emailing people and letting them know my ISP & email address had changed yet again. So I found Yahoo Mail about 3 or 4 years ago and have stuck with it ever since.
Yahoo Mail is very simple to use. Yahoo also allows you to have multiple email addresses. This always comes in good if you subscribe to several things online and you know you will be sent lots of junk mail. Instead of signing up with your regular email address, you can use another yahoo email address and designate that as your junk mail account.
Yahoo Mail is web only, which means you can access it from any computer that you visit. Your yahoo mail password is secured, and if you forget it, or if someone tries to access your account, they need to have the answer to your secret question. Your secret question though is a question that you designate. So it could be anything from Wheres my birthmark to what surgery did I have? In other words, you can have the question be only something that you know the answer to and do not have to worry about someone else getting your password.
Yahoo Mail also offers different folders. They have a bulk mail folder in which you can have bulk mailings go into this folder. They also offer you 6MB of space.
When you delete your email, it goes into the trash folder. So if you deleted something by mistake, you can retrieve it from the trash folder. When you are reaching your 6 MB of space, you can delete your trash folder contents to make more room for more emails.
Yahoo mail also offers your basic stuff that can be found on other email providers, such as a signature in your emails, an address book, you can make up other folders and put the emails in them as you read them. For instance, you may make up a mouthshut folder and put all email correspondance from mouthshut into that folder.
I highly recommend Yahoo Mail. Yahoo has its up & downs and you may found the email to be unaccessable for a short period of time, but all email providers & ISPs go through that.