I got it working! The behavior I encountered in doing so was unexpected though.
Here are the steps I did:
- In ‘uncategorized’ settings I entered ‘users@rust-lang.org’ for ‘custom incoming email address’
- Click ‘save changes’
- Changes appear to save successfully.
- Go back into the settings for ‘uncategorized’ and the ‘custom incoming email address’ is empty.
That is where I got confused.
- Went to another category and entered the same email address, click save, got an error message.
So that clued me in that maybe the original attempt did work. Sending emails does create uncategorized topics now.
Thanks for your help @riking