How do I troubleshoot or fix transaction logs created every minute?

I have Exchange Server 2003 and I noticed that Outlook 2003 was running extremely slow.

Checked server. It, too, was running slow.

Checked MDBDATA folder. Noticed that a transaction log was being created every minute causing low disk space rapidly.

Read that selecting Circular Logging would help clear the logs, and it did, but the next day the server and Outlook starting running slow again.

FYI: In testing all possiblities, I stopped the Default Website in IIS and the transaction logs did not populate every minute.

If anyone could offer direction or help me figure out what else I could check and/or do to fix this issue I’d greatly appreciate it.

Thanks!