someone please help me with this!!

Either your email server is offline or misconfigured in Mail, or your cable/DSL service is down.

If it's not one of those problems, then it may be how you've configured your email client. When it happens to me I've generally discovered that I did not correctly specify the correct method of authentication. Open your client's pfreferences to locate the server list. You should have an option for setting authentication for each server. Check to be sure you are using the one specified by your email ISP.

For example, a commonly used method is called Password. It requires that you provide your email username and password to access the SMTP server to send mail. But some providers use different methods of authentication, so you need to check with your mail provider to be sure you configure this correctly for them.

Your provider may have a page on their website with instructions on configuring a Mac client for their mail service. Or you can call their help line for assistance with the problem.