Wie richte ich eine Willkommens-E-Mail ein, die gesendet wird, sobald sich ein Benutzer anmeldet?

[nolo (Manuel)]

I think the first automated message comes when a user spends about 15mins browsing a forum and is then promoted to trust level 1. I wrote up a guide how to use these system message to welcome new user:

Welcome new users with customized trust level promotion messages

The default on-boarding journey is set up using the Discourse narrative bot. It’s a great feature in general, but at times you might not want to welcome new users with a bot. This howto lists the steps involved to set up on-boarding with the trust level messages sent by the site contact user. Set up the site contact user All automated messages are sent by the site contact user. It’s the system user by default. You can change this by modifying site contact username in Settings: [Screenshot from…

Maybe not a solution depending what exactly you want to achieve though. In the line what @pfaffman suggested you could also look at Discourse modules on Make.