SaaS Founders: What tools do you use for transactional emails in your SaaS product?

I started using Postmark but got to know that there free plan only provides 100 emails per month. Sendgrid allows 5000 emails per month in their free plan but they do not let me sign up for a new account for no reason. It's quite important for me to have templates to send magic links, welcome emails, billing emails, etc.