This email scam hits you right where you live... in your email account! They send you an email that is intended to elicit a quick response. Naturally, nobody wants to have their email account limited or deleted so we instinctively react to the warning so we can clear the "problem" up as quickly as possible. But that is exactly what the scammers are hoping will happen. They are counting on the fact that most people will have a knee-jerk reaction and click on the link without taking the time to slow down and think.
Consider a few things before you go clicking. Why would your service provider tell you your mailbox is filling up, by filling up your mailbox? I thought the whole thing looked just a bit suspicious when the email was sent to me and I am the Webmaster.
Another indicator is the link address. For those who are viewing their mail on a desktop, you can hover your mouse over the link ***WITHOUT CLICKING*** and see the link it will take you too. (Usually in the bottom left corner of your screen) It will certainly be to an address you are unfamiliar with.
If you are in doubt about your account, contact your provider directly either by phone or online with a link you know to be good.
Always take a minute to check out any link in an email. The few seconds you take can save you hours of headaches.