While chosing an email provider to go above the free rate limit from Supabase I stumbled upon this article basically saying that Resend is a wrapper around Amazon SES, thus recommending to use SES directly

https://matteosonoio.it/resend/

Resend presents itself as being a dev-friendly email provider that "just works" while AWS SES (simple email service) is the complex but performant alternative.

After a whole day of configurations in the AWS console I still couldn't send one single email, let alone setup logging and the likes.

When going back to Resend, I managed to send my first email in literally 1mn. The whole Supabase integration took 15mn.

You do the math.

No actually I'm gonna do it:

This is the cost per email for both of these services:

• SES: $0.0001
• Resend: $0.0004

It really depends on what you're gonna use mails for, but if you only use transactional emails (signup, invites, order confirmations), you might send 10 of them per users per day, so 300 emails per months per user, which gives an email cost per user of:

• SES: $0.03 / user / month
• Resend: $0.12 / user / month

However keep in mind that you have to pay your engineer to setup the whole thing and Resend makes you save a lot in that regard, at least in my personal experience:

• SES: 15 hours = $1500
• Resend: 15mn = $25

You can plug in your own numbers, but over one year, SES only gets cheaper when you have:

cost_ses = 1500 + 12 * 0.03 * nb_users
cost_resend = 25 + 12 * 0.12 * nb_users
cost_ses < cost_resend
1500 - 25 < 12 * (0.12 - 0.03) * nb_users
1365 < nb_users

at least 1365 users. And that's if you intensively use emails. So while SES is cheaper than Resend, I'd recommend to always start with a dev-friendly provider like Resend to start your project, then optimize by directly using the underlying cloud provider directly.