Laravel 10 with Mailgun API returns 530 5.7.1 Authentication required error

[John_Clever]

I’m getting an authentication error when trying to send emails through Mailgun in my Laravel 10 project. Here’s my setup:

I have a Mailgun sandbox domain configured:

sandbox7789123b456ef78a9.mailgun.org

I generated a new sending API key from the Mailgun dashboard and added it to my Laravel environment configuration:

MAIL_DRIVER=mailgun
MAILGUN_DOMAIN=sandbox7789123b456ef78a9.mailgun.org
MAILGUN_SECRET=bbbbbbbb-84g856-673d8

I’ve also added my test email address to the authorized recipients list in the sandbox settings. However, whenever I attempt to send an email, I keep receiving this error message:

530 5.7.1 Authentication required

I’ve double-checked my API key and domain settings multiple times, but I can’t figure out what’s causing this authentication failure. Has anyone encountered this issue before? What could be the missing piece in my configuration?

[josephk]

This error happens when Laravel can’t authenticate with Mailgun’s servers. A few things usually get missed beyond basic setup. First, double-check your API key format - it needs to start with ‘key-’ then your actual secret. Second, see if you’ve got firewall or network restrictions blocking HTTPS requests to Mailgun’s endpoints. I’ve hit similar issues working behind corporate proxies that needed extra SSL certificate handling. Also, sandbox domains have specific limits and sometimes act weird with authentication headers compared to production domains. Try testing with a verified production domain if you can - helps figure out if it’s sandbox-specific weirdness.

[Bob_Clever]

check your config/mail.php - make sure u r actually using the mailgun driver. laravel sometimes ignores MAIL_DRIVER=mailgun in .env and defaults back to smtp. also verify ur mailgun secret has the ‘key-’ prefix - api calls won’t work without it.

[FlyingStar]

Had the same problem with Mailgun and Laravel. The auth error usually comes down to config issues. Make sure you’ve got MAILGUN_ENDPOINT in your .env file - that’s what tells it which API endpoint to hit for your region. Most people need MAILGUN_ENDPOINT=api.mailgun.net, but if you’re in the EU, use api.eu.mailgun.net instead. Use your Private API key, and after you update .env, run php artisan config:clear to refresh the config cache. That last step fixed it for me.