It works again.

But why? Suddenly it does not works. Gmail has a limit sending mails?

Follow google's support

- Sign in to your account from the web version of Gmail at https://mail.google.com. Afterwards try accessing your messages in your mail app again.
- If you're still having problems, visit http://www.google.com/accounts/DisplayUnlockCaptcha and sign in with your Gmail username and password. If necessary, enter the letters in the distorted picture.
- Your mail app might not support the latest security standards. Learn how to allow less secure apps access to your account.
- Make sure your mail app isn't set to check for new email too frequently. If your mail app checks for new messages more than once every 10 minutes, the app’s access to your account could be blocked.
Try changing your password according to our tips on creating a strong password.

It's obviously an issue with Gmail, not laravel. You'd have to check with google to figure out what happened. The better solution is to NOT send mail from ANY public mail provider and use a service like mailgun or mandril.

cringer said:

It's obviously an issue with Gmail, not laravel. You'd have to check with google to figure out what happened. The better solution is to NOT send mail from ANY public mail provider and use a service like mailgun or mandril.

Can you explain me why is better using mailgun or mandril?

Any public mail provider is open to the masses and have a lot of restrictions in place. They are constantly abused causing IPs to become blacklisted which commonly affects other users. Changes to the service such as outbound restrictions can happen at will with no notice and technical support with them is typically slim to none.

Services like mailgun or mandril are dedicated for sending reliable mail.