"Disk space notification" mails sent to mailboxes having autoresponders

Problem reported by Sébastien Riccio - 9/10/2024 at 9:05 AM

Submitted

Hello,

While debugging some stuff, I noticed that when SmarterMail send a "disk space notification" e-mail to a local account that has autoresponder enabled, the autoresponder tries to autorespond to the notification.

For this SM tries to send the autoresponder e-mail to <System Administrator@System Administrator>.

I see that in the disk space notification e-mails and other SM notifications, there is this header.

X-SmarterMail-Event: true

Shouldn't the auto responder logic skip the auto response when it detects this header ?

I guess it would then stop trying to reply to system notifications...

Kind regards

Sébastien Riccio

System & Network Admin

https://swisscenter.com

4 Replies

Reply to Thread

Jereming Chen Replied

9/10/2024 at 9:53 AM

Employee Post

Our Autoresponders should skip event messages with headers like that. I have personally tested this scenario a couple months back but have not seen it reply like this. That being said, I am glad that autoresponders are limited to 1 response per 24 hours per recipient to avoid autoresponder storms. I will try to test this in our testing environment and see what's going on.

Jereming Chen

Internal Network/System Administrator

SmarterTools Inc.

www.smartertools.com

Sébastien Riccio Replied

9/10/2024 at 10:38 AM

Hello,

I've discovered this while testing latest build on linux, with a config only copy of the domains/mailboxes we have on our production rig (windows) but with a "fake" outgoing gateway configured, so that no mails can escape to the outside by error.

By fake, I mean, instead of setting our usual outgoing gateway in this test rig, I've set a local gateway simulator that catches all outgoing mails sent by SmarterMail.

hxxps://mailcatcher.me/

Note that this test server is not receiving any mails from the outside, so all mail that SM tries to send are event related e-mails.

That's where I discovered SM was attempting to send into the wild some auto responder, responding to system messages... (mainly disk space notifications)

Sébastien Riccio

System & Network Admin

https://swisscenter.com

Sébastien Riccio Replied

9/10/2024 at 10:47 AM

By the way, here is an example notification mail that triggers the auto responder:

Received: ; Tue, 10 Sep 2024 00:17:36 +0200
X-SmarterMail-SpamAction: None | NoAction
X-SmarterMail-TotalSpamWeight: 0 (Authenticated)
From: 
Date: Tue, 10 Sep 2024 00:17:36 +0200
Subject: Disk space notification
Message-Id: <c2d2340f521a4cffb4857499d99742dd@fc46c7e4fe914c3e861f3cbcbacf69cb>
To: some@localuser.com
X-SmarterMail-Event: true
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="=-OFdzMzUmufJ5bl1lITC1LQ=="

I see the From: is empty (strange) but the X-SmarterMail-Event: true header is present.

The event is configured like this (we didn't modified it on this test installation)