Assuming the Cloudmark Desktop One toolbar appears after reinstalling, you can start adding back your other third party add-ins one by one until you discover which one is causing the conflict.
At that point, you'll need to decide whether you want to keep Cloudmark Desktop One or the add-in causing the conflict.
The result is that your list of rules will be hard to manage, it is easy to end up with duplicate rules and messages could get duplicated or end up in the wrong folder because of conflicting or incorrectly sorted rules.
This results in quite large display names which aren’t always meaningful, get truncated or clutters the Outlook interface more than it should.Clicking on the "Software" heading will order the list so that the Outlook add-ins appear together.Temporarily disable the Outlook add-ins by right clicking on them and choosing Change Start Mode and then choosing Disabled. If the Cloudmark Desktop One toolbar doesn't appear, try reinstalling Cloudmark Desktop One.I've added a calendar to my work Outlook with all of work holidays.And though it shows the second calendar next to my primary, if I schedule anything for a day that is filled on the internet calendar it will show "no conflicts".