Yes, writing messages to another custom group works fine. It also works for trust_level_2 and trust_level_3. But unfortunately there is only a 503 error for trust_level_0 and trust_level_1. Is there a setting preventing sending messages to these groups?
I want to message the users about promotional stuff and it imperative that they receive a notification about these posts (on the upper right corner). I am not sure if there is a simpler way to do that. Making a forum post does not guarantee a notification delivery unless the user is mentioned.
Discourse is not really a mass mailing tool for sending “promotional stuff”. You want to use mailchimp or some other newsletter sending tool for this purpose. The admin user list has an export link so you can easily get the most current user list on a regular basis and then invite them to subscribe to your mailchimp.
One approach you can take is to create a category for announcements. Then in the user preferences admin settings you can add this category to the “default categories watching” setting. That way people will be notified whenever you post an announcement.
I don’t know why the error message is so cryptic. Someone more familiar with this can respond.
I’m bumping this again because I’d really want to know why group messages do not work for certain groups and if we should open a bug report for Discourse (unless it is intended behaviour)
I message TL0 occasionally- worked for me as recently as 5 days ago. For the group settings I have “who can message this group” set to “only admins”.
I use it for ephemeral messages like service outages that are not critical and I don’t want to persist forever. But the Announcements category is a good idea.