I'm trying to set Mailgun up on Craft (Like we've done plenty of times before) but each time it keeps saying that the connection to SMTP is failing.
The error I'm getting is:
2017/03/29 09:54:13 [error] [application] Email error: SMTP Error: Could not authenticate.
I've checked https://craftcms.com/support/troubleshooting-email-errors#dealing-with-errors and error description is:
“Use SMTP authentication” was checked, but the credentials were incorrect.
But I've double checked these details over 10x now and they are 100% correct.
Is there any other reason this could fail? We're using port
587 and tried other ports but no success. Even opening these ports on the server doesn't connect.
Where would the problem be... Craft, Mailgun or Server?