Should I include countdown timers in emails?

I'm exploring ways to increase email marketing conversion rates and have heard about using countdown timers, but I'm unsure about their effectiveness. I want to understand the potential benefits, best practices, and potential drawbacks of implementing countdown timers in email campaigns. My goal is to create a sense of urgency without appearing too aggressive or spammy, and I need concrete guidance on how to integrate these timers strategically into my email marketing efforts.