Thunderbird email stopped receiving new emails about mid-afternoon two days ago. Now the only way to received new email is to turn off security. Outgoing emails are unaffected. When attempting to receive emails following security re-initiation, the following message is displayed: "The certificate for Wowway.com is not valid for that server. . . ." Wowway (WOW!) cannot help. Please keep response as non-technical as possible, as I am a novice.