Unfortunately, no it doesn’t work.
unchecking “Use SSL for SMTP” gives me the following error message :
Which is strange because I know my credentials are correct.
Looking with tcpdump, it behaves like I’ve explain for the “Discourse-doctor and rake” case.
The exchanges between Discourse and the smtp server looks like the following
< 220 [redacted] ESMTP ready
> EHLO [redacted]
< 250-[redacted]
< 250-PIPELINING
< 250-SIZE 36700160
< 250-ENHANCEDSTATUSCODES
< 250-8BITMIME
< 250 STARTTLS
> AUTH PLAIN [redacted]
< 500 5.5.1 Invalid command : commande not supported
It’s as though Discourse is not trying to initiate STARTTLS ; It’s exactly as described in the post I’ve linked to in my previous post.