Upfort Shield has no known conflicts and many of our users appreciate being able to layer Shield with their existing tools for an extra overlay of security.
Our Inbox Defender scans the email when it is opened and should not interfere with other email security tools that complete the scan before the email lands in the inbox.
Our Browsing Protections similarly check the URL as you navigate to it at the browser level. Other browsing protection tools will interact and block urls at a different level from us which helps to avoid conflicts.