For the average person, you will likely have more than one email address going to your Android phone.
Below is a run through on how-to set up a basic non-Google email on your Android device. Some email providers may need special server or port settings. If you follow these steps, this will explain how to input those settings.
Step 1. Open the email application by pressing the Email or Mail icon.
Step 2. What you will see is a couple of text boxes asking for your full email address and your password. Type in your email address and password exactly like you would when logging into your email account.
Step 3. Once you have entered your login credentials, you will need to select what type of email service you are using. I would recommend the IMAP setup if possible. This will usually give you the access to your folder and other options.
Step 4. The screen you will see for POP and IMAP are very similar. You will need to check over your incoming mail server information. If you are experiencing difficulties, there are usually setup instructions in the help section of your email program. Many of these instructions will have the settings for mobile devices such as your Android phone.
IMAP settings for Google Apps: https://mail.google.com/support/bin/answer.py?answer=114408
Here is a link to the settings if you use Yahoo Business mail: http://help.yahoo.com/l/us/yahoo/smallbusiness/bizmail/pop/pop-33.html
Step 5. Once you have looked over and modified the settings if needed, you can press the Next button at the bottom left of the screen. This will bring you to the Outgoing server information. Again, look over the settings and make sure the they are correct and press Next.
Step 6. The next screen will ask you to give this email account a nickname. This step isn’t required, but if you have more than one email account on your Android phone, it will help you determine which is which.
In this step, you will also be asked to enter your name. This is the name the recipient will see when you sent them an email.
Step 7. Click Done in the bottom right corner. The next screen will ask you how often you would like the Android phone to automatically check your emails. If you have it check too often, you will likely see a decrease in battery life. 30 minutes is usually a good interval.
Step 8. Once you select the frequency for it to check your email, you are pretty much done.