Please enable JavaScript to view the comments powered by Disqus.

Which Email Service Provider Should You Use in 2025? Postmark vs Mailgun

Email is a core communication channel we rely on at Hozuko, Singapore's direct-landlord property rental platform. We primarily send transactional emails, not marketing emails. This write-up evaluates email providers from that perspective.

Here are some popular options:

  1. Amazon Simple Email Service (Amazon SES)
  2. Postmark
  3. Resend
  4. SendGrid
  5. Mailgun

Initially, I assumed these services were more or less the same—so I didn’t think my choice would matter much.

Oh boy, was I wrong.

I had a horrible experience with Mailgun.


TL;DR: I had serious deliverability issues with Mailgun. Support took 2–3 weeks to respond, claimed they fixed the problem (they hadn’t), and pushed me to upgrade. I upgraded—still broken. I filed another ticket and waited again. Eventually, I switched to Postmark and had a flawless experience. Here’s what happened.


Comparing Postmark to Mailgun

Email Open Tracking

Before the deliverability issues, I encountered a peculiar problem with Mailgun’s open tracking: every email was marked as “opened” just one second after delivery.

Their response:

This can happen due to antivirus software, spam filters, or email clients that auto-open messages. We recommend using tags to view unique opens.

Fair enough. I implemented a workaround to ignore instant open events.

After switching to Postmark—no such issue.

IP Reputation

Checked via SenderScore:

Postmark separates transactional IPs from bulk email pools. Mailgun doesn’t. I was repeatedly assigned low-reputation IPs that caused Microsoft to block my emails.

When I raised this with Mailgun, their excuse was:

There will always be risks associated with shared IPs... think of it like a highway: multiple drivers share the risk of its use, but still choose to use it in order to benefit.

I can’t justify using a dedicated IP—I don’t send enough volume, nor do I have the capacity to manage it.

Meanwhile, Postmark just worked.

Email Logs

UI/UX

Customer Support


Conclusion

I can’t speak for every email provider—but I can confidently compare the two I’ve used.

❌ Don’t use Mailgun:

✅ Use Postmark:


If you’re sending transactional emails in 2025, skip the frustration.
Go straight to Postmark.