Mail is telling me I have exceeded my daily limit of sent emails...

Greetings,

I went to send an email via Mail today and got a message telling me I had exceeded my daily limit for sending emails. It stated that I had sent 200 something emails and that my limit would reset in 12 hours.

I have not sent anywhere near that amount. I checked my "sent" box and it confirms this. I browsed through my "junk" and found a bunch of Delivery Status Notification notices from "mailer-daemon@secureserver.net" telling me an SMTP connection could not be established etc.

So Im thinking someone or something has invaded my email system and is sending out spam or something to all in my address book?

I have three email addresses : an icloud, an gmail and one under my name via godaddy. I primarily use the one with my name when using email or entering email information when required on sites. All three are routed to my Mail account on my mac and iphone and Ipad. I have searched online for solutions and some say I need to re-do my email password...does that mean here on my apple Mail account? Or on all of the three?

I dont know where to begin to address this issue-- anyone have any ideas? Mahalo!