Have you ever been without your email, and felt totally unconnected to the world. You could be missing some important information, and it is all because you cannot get into your account.
A popular scam right now preys on that fear people have of not being able to get at their email accounts, and to make these scams work the scammers make it look like the emails are coming from your email provider. The emails will tell you that you have exceeded your mailbox quota or that someone has attempted to access your email account. Either way, the email then asks for you to update your information within a set amount of time or your email account with be closed permanently.
If there ever was a real problem with your email account, your provider would not send you an email about it, and they would not set a time limit on when you have to respond by. Not everyone checks their email daily, or even weekly, so if they are telling you to complete the task by a set date they are doing it to scare you into moving fast, without looking into things first.
If you do get an email like this, and you are worried that there really COULD be a problem with your email account, call the customer service number for your email provider . . . but do not call any customer service numbers listed in the email . . . those will be fake also. Use a search engine to look up the customer service number so that you know for sure that you are contacting the right people to check on your account.