email account stopped working

when I opened Mail, my messages downloaded as usual. The only difference was that messages I usuall have sent to special folders arrived in the in-box. When I tried to open a new message, the header information, and the from/to information appeared, but the message content was blank. Old messages still display content when opened. Since this happened, I have not been able to receive any email. I can send email messages. My husband's account on the same iMac is fine. I can still access my email through my MacBook Pro. How can I fix this?

Thanks!!