Hey there! We've found the following might help you get unblocked faster:

• 🧵 500 Error code on POST related to email service

• 📚 Use Cases

• 🧵 Getting false "Deploy Crashed!" emails during normal deployments

• 📚 Deploy an Express App

If you find the answer from one of these, please let us know by solving the thread!

Is there any error message in the log? It would be helpful if you could attach the log here

From your example, it might be because you didn't await the function, you might need to
`email = await resend.Emails.send(params)`

here's the error log: https://prnt.sc/VDl7gw-lD8_J

Note: However everything is working fine while I'm running locally.

how come? am not using async function also, if that's the case then i won't be able to use locally right?

This looks like it’s your custom error handling message, just to make sure, you’re hardcoding the api key or you put it as environment variables? Perhaps you forgot to add your api key into environment variables on Railway

Kindly check if the API key on Resend if it’s still valid

I've set my API key in the environment variables, and here is my celery task that I'm using to send emails.

from celery import shared_task
from django.conf import settings
from django.template.loader import render_to_string
import resend
import logging

logger = logging.getLogger("user_management")

resend.api_key = settings.RESEND_API_KEY

@shared_task
def send_otp_email(email, otp, otp_for="account verification"):
    """Send OTP email asynchronously using Resend API"""
    subject = "Your OTP"
    html_message = render_to_string(
        "otp_email.html",
        {
            "otp": otp,
            "otp_for": otp_for,
            "expiry_minutes": settings.OTP_EXPIRY_TIME // 60,
        },
    )
    try:
        params = {
            "from": settings.DEFAULT_FROM_EMAIL,
            "to": [email],
            "subject": subject,
            "html": html_message,
        }
        response = resend.Emails.send(params)
        logger.info(f"OTP email sent to {email} via Resend API: {response}")
        return f"Email sent to {email}"
    except Exception as e:
        logger.error(f"Failed to send OTP email to {email} via Resend API: {str(e)}")
        return f"Failed to send email: {str(e)}"

As I mentioned in the earlier comment, it's working locally without any issues.

Just to confirm, is the env ‘RESEND_API_KEY’ on Railway is setup?

yes, check here: https://prnt.sc/lPAFY5-wWGx_

I saw your host email is using ‘onboarding@resend.dev’ which is a test email, if you want to simulate successful email send, maybe try ‘delivered@resend.dev’

let me try

Fwiw you should probably not be sharing screenshots of your API keys.

Thank you, I already removed it.

Thanks, everyone. It's working now. After doing some research, I found that the issue wasn't in my code or the railway server.
Here's the resend error log:

You can only send testing emails to your own email address (the one associated with the email address I used to create the resend account). To send emails to other recipients, please verify a domain at resend.com/domains, and change the from address to an email using this domain.

I fixed it just by adding and verifying my domain on their platform.