Discourse with Proxy nginx. Site worked including email, but emails are no longer sent without log error in discourse. Trying to trace the problem down, I found
======================================== Discourse 2.7.0.beta1 Discourse version at irusweg.de: Discourse 2.7.0.beta1 Discourse version at localhost: NOT FOUND ==================== DNS PROBLEM ==================== This server reports NOT FOUND, but xxx reports Discourse 2.7.0.beta1 . This suggests that you have a DNS problem or that an intermediate proxy is to blame. If you are using Cloudflare, or a CDN, it may be improperly configured.
I am aware that this is not a Discourse problem, but rather one of proxy configuration. Nevertheless, any hint would be helpful.
For a robust test, get an address from http://www.mail-tester.com/ Or just send a test message to yourself. Email address for mail test? ('n' to skip) [email@example.com]: firstname.lastname@example.org Sending mail to Testing sending to xxxxx using myserver:587. = ERROR ======================================== UNEXPECTED ERROR 500 5.5.1 Invalid command