If the cap is screwed on and sealed, you should pour it from the side like a bottle of oil: https://www.team-bhp.com/forum/attachments/technical-stuff/1...

I guess you use different types of teapots, the ones I ever saw were definitely not waterproof, nothing to screw. Maybe some small lip to keep it in place but when put on the side they would probably fall off, pouring hot liquid everywhere.