Updated by Holger Just 7 months ago
Registration email from redmine.org triggers the following rspamd symbol:
From the headers:
Received: from static.18.104.22.168.clients.your-server.de ([22.214.171.124]:43352 helo=Ubuntu-2004-focal-64-minimal)
I think this HELO Ubuntu-2004-focal-64-minimal is what rspamd takes offense at. It should probably be a FQDN.
But TBH I was not able to figure out what exactly the rspamd symbol meant quickly so this might be wrong.
See https://www.rfc-editor.org/rfc/rfc5321.html#section-126.96.36.199 which says
These commands are used to identify the SMTP client to the SMTP
server. The argument clause contains the fully-qualified domain name
of the SMTP client, if one is available. In situations in which the
SMTP client system does not have a meaningful domain name (e.g., when
its address is dynamically allocated and no reverse mapping record is
available), the client SHOULD send an address literal (see