When It’s Not Your Bug: My SMTP Struggles on Render Free Tier

Some developer days are smooth. Others are battles. This was definitely one of the battles.

It started simple enough. I had set up password reset emails for my application. Locally, everything was running perfectly. The templates looked clean, the buttons worked, and I could receive emails instantly. I felt confident pushing it to production.

Then came deployment on Render. That’s when everything fell apart. Suddenly, the emails stopped working. The server logs were showing strange errors, and not a single email was being delivered.

My first assumption was simple: “I must have messed up when I changed the email templates.” So I rolled back those changes. No luck. I added more logs. Still nothing. I redeployed multiple times. Same result.

Hours kept slipping by. Frustration built up. I started experimenting with different providers and libraries. I tried alternatives to Gmail. I tried using Resend. I even considered using Nodemailer with different SMTP configurations. Nothing worked. Locally, my code was fine. On the server, it was dead in the water.

At one point, I was so frustrated I thought about moving the entire project to another hosting service. Maybe it was a Render issue, I reasoned. If I just deployed somewhere else, maybe it would magically fix itself.

Finally, after wasting almost an entire day, I reached out to Render support. That’s when the truth finally came out:

Your SMTP connection timeouts are likely due to recent changes we implemented. Free web services can no longer send outbound traffic to SMTP ports 25, 465, and 587 as of September 26th, 2025.

To resolve this, upgrade your free web service to any paid instance type - this removes the SMTP port limitation and will restore your email functionality.

Alternatively, consider using external email providers like Mailgun, SendGrid, or Postmark for increased reliability and reduced spam risk.

Port 25 remains blocked for all services (free and paid) as we run on Amazon EC2, but ports 465 and 587 work fine with paid instances.

— Render Support

So there it was. After hours of chasing non-existent bugs, the issue had nothing to do with my code at all. It was the environment. Render had introduced a new restriction: on the free tier, outbound SMTP is blocked.

In hindsight, it makes sense. Blocking SMTP on free instances prevents abuse and reduces spam risks. But in the moment, it was maddening. I had lost an entire day convinced I had broken something, when the truth was the platform itself had changed.

Looking back, the key lesson for me is this: not all errors are yours to fix. Sometimes, the limitation comes from the infrastructure. And sometimes, the fastest way forward is to ask the right question to the right people instead of debugging endlessly in circles.

So if you’re using Render’s free tier and wondering why your emails don’t work anymore—now you know. It’s not you. It’s the ports.