On Resend.com

There’s this new startup, Resend.com, which promises to be the “best email API” for developers. Their focus is the developer experience of the platform, which is quite clear just by looking at their homepage.

Unfortunately, it doesn’t take much to find out that they’re basically just a wrapper of Amazon SES, or Simple Email Service, the email sending service by Amazon Web Services.

You can see that from the headers of emails sent through the platform:

Received: from a9-6.smtp-out.amazonses.com (a9-6.smtp-out.amazonses.com [54.240.9.6])
	(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	(No client certificate requested)
	by [...]
Message-ID: <0100018917ddfdb5-88eb8ffc-2e10-4b46-85ec-d1f24901eabb-000000@email.amazonses.com>
X-SES-Outgoing: 2023.07.02-54.240.9.6

Or also in their own documentation, which tells you to add the SPF DNS record of Amazon SES:

"v=spf1 include:amazonses.com ~all"

There’s also obviously a markup on pricing:

• Amazon SES costs $0.10 per 1k emails (no free emails if you send from outside AWS).
• Resend is free for the first 3k emails, and then the cheapest plan is at $20 for 50k emails, or $0.40 per 1k emails.

That’s 4 times the Amazon SES pricing (not considering the free emails).

What’s the problem with Resend relying on Amazon SES for sending emails?

1. You would expect an email sending service to have an actual email sending infrastructure, and not just wrap another API.
2. Amazon SES doesn’t have the best reputation: their very low pricing, combined with the not-very-strict rules they have, make SES an easily abused service. It’s not the first service that comes to your mind if you care about deliverability or reputation of senders.

Now, it’s very well possible that Resend has their own dedicated IPs and manage them in a careful way (e.g. separating transactional emails from bulk emails), but there’s no mention of that on their website.

From what we know, they could just be wrapping a 5-line API call to Amazon SES and charge 4x for it.

The disappointing thing about all of this is that they’re not being transparent at all about whay they’re doing, and this makes me stay away from them.

If I wanted to use Amazon SES, I’d just use Amazon SES, and save money in the process. I understand that their selling point is the developer experience, but not being transparent about the fact that they don’t have an email infrastructure isn’t a detail.¹

I asked them on Twitter if they plan to buld an email infrastructure in the future, and I’m waiting for a reply.