Thunderbird stopped retrieving my email but gives no error messages

When I started Thunderbird this AM it did not retrieve my email. I have multiple email accounts. It is retrieving my gmail using Imap but my pop mail is not being retrieved. I have tried specifically retrieving one pop account. It displays "connecting to pop.pracsolinc.com" on the bottom and a full green progress bar. After about 30 seconds that goes away. No mail is retrieved and no error is displayed. These settings all worked yesterday but today... not so much. I fired up my copy of outlook 2010 which I haven't used in months. It works fine. Please help me. I don't want to use outlook. I like Thunderbird much better. I also tried rebooting but it had no effect.