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Defect #38514

open

Email Notifications: Email Notifications: trigger rspamd symbol for bad HELO

Added by Hendrik Jaeger over 1 year ago. Updated over 1 year ago.

Status:
New
Priority:
Normal
Assignee:
Jean-Philippe Lang
Category:
Website (redmine.org)
Target version:
-
Start date:
Due date:
% Done:

0%

Estimated time:
Resolution:
Affected version:

Description

Registration email from redmine.org triggers the following rspamd symbol:
Symbol: HFILTER_HELO_5(3.00)

From the headers:
Received: from static.126.101.4.46.clients.your-server.de ([46.4.101.126]: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-4.1.1.1 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
   Section 4.1.3).

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 #1

Updated by Hendrik Jaeger over 1 year ago

Sorry, pressed enter at the wrong time before I even really started …

Subject should read: Email Notifications: trigger rspamd symbol for bad HELO

Description:

Registration email from redmine.org triggers the following rspamd symbol:
Symbol: HFILTER_HELO_5(3.00)

From the headers:
Received: from static.126.101.4.46.clients.your-server.de ([46.4.101.126]: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-4.1.1.1 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
   Section 4.1.3).

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 #2

Updated by Holger Just over 1 year ago

  • Subject changed from Email Notifications: to Email Notifications: Email Notifications: trigger rspamd symbol for bad HELO
  • Description updated (diff)
  • Category set to Website (redmine.org)

I'm editing the issue with the details from #note-1

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 #3

Updated by Holger Just over 1 year ago

  • Assignee set to Jean-Philippe Lang

Here, the MTA must be configured to use the external hostname of the server as a HELO. For that to work correctly, the following steps are required:

  • The mailserver (MTA) must be configured to use use a valid hostname as its HELO name. For psotfix, you can configure this with the smtp_helo_name option on main.conf. This uses the myhostname value by default. Most likely, you thus want to just set myhostname to redmine.org in the main.conf to resolve this.
  • The reverse DNS name for the IP address of the sending server must be set to this name, thus probably to redmine.org. As the server is hosted by Hetzner, you can change this in the in the server admin interface at https://robot.hetzner.com at the respective server -> IPs and click on the text field at right next to the correct IP address.
  • The DNS name configured for the IP address must again resolve back to the IP. This is currently the case when using redmine.org.
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