I understood that HTTPS is recommended, but our networks don't permit this now.
We have a working smtp relay, and since years we rely on this for autosupport, and it seems supported (while not preferred now). If SMTP support is to be dropped, I missed the announce.
The problem here is that netapp's MX servers were rejecting autosupport mails without any explanations, I consider this as a service failure, not a config problem on our side.
Anyway, it seems to have been corrected yesterday 20:38 CET … Hope this won't repeat !
Once again, if SMTP support is to be dropped, please let your customer know *before* dropping 🙂