Gmail suddenly blocking server notifications

[kgs]

Howdy,

Two days ago, gmail started blocking delivery of normal server notifications. Other email from our IP is delivering to gmail fine. Here is an example:

Date:	Thu, 10 Feb 2022 00:38:16 -0800
From:	Mail Delivery System <[email protected]>
To:	[email protected]
Subject:	Mail delivery failed: returning message to sender
Auto-Submitted:	auto-replied
Content-Type:	multipart/report; report-type=delivery-status; boundary=1644482296-eximdsn-284889137
Message-Id:	<[email protected]>
MIME-Version:	1.0
Received:	from mailnull by server.myserver.com with local (Exim 4.94.2) id 1nI4y0-0005OI-Ry for [email protected]; Thu, 10 Feb 2022 00:38:16 -0800
References:	<[email protected]>
X-Failed-Recipients:	[email protected]

--1644482296-eximdsn-284889137

Content-type: text/plain; charset=us-ascii


This message was created automatically by mail delivery software.


A message that you sent could not be delivered to one or more of its

recipients. This is a permanent error. The following address(es) failed:


  [email protected]

    host gmail-smtp-in.l.google.com [142.250.141.27]

    SMTP error from remote mail server after end of data:

    550-5.7.1 [66.*.*.*      12] Our system has detected that this message is

    550-5.7.1 likely unsolicited mail. To reduce the amount of spam sent to Gmail,

    550-5.7.1 this message has been blocked. Please visit

    550-5.7.1  https://support.google.com/mail/?p=UnsolicitedMessageError

    550 5.7.1  for more information. c9si791973pjr.56 - gsmtp


--1644482296-eximdsn-284889137

Content-type: message/delivery-status


Reporting-MTA: dns; server.myserver.com


Action: failed

Final-Recipient: rfc822;[email protected]

Status: 5.0.0

Remote-MTA: dns; gmail-smtp-in.l.google.com

Diagnostic-Code: smtp; 550-5.7.1 [66.*.*.*      12] Our system has detected that this message is

550-5.7.1 likely unsolicited mail. To reduce the amount of spam sent to Gmail,

550-5.7.1 this message has been blocked. Please visit

550-5.7.1  https://support.google.com/mail/?p=UnsolicitedMessageError

550 5.7.1  for more information. c9si791973pjr.56 - gsmtp


--1644482296-eximdsn-284889137

Content-type: message/rfc822


Return-path: <[email protected]>

Received: from [127.0.0.1] (port=35224 helo=localhost.localdomain)

    by server.myserver.com with esmtpa (Exim 4.94.2)

    (envelope-from <[email protected]>)

    id 1nI4xz-0005O8-On

    for [email protected]; Thu, 10 Feb 2022 00:38:15 -0800

Date: Thu, 10 Feb 2022 08:38:15 GMT

From: "cPanel on server.myserver.com" <[email protected]>

Message-Id: <[email protected]>

Reply-To: "cPanel on server.myserver.com" <[email protected]>

Subject: [server.myserver.com] The backup process completed.

To: <[email protected]>

X-iContact_locale: en

Mime-Version: 1.0

Content-Type: multipart/mixed; boundary="mixed-Cpanel::Email::Object-20715-1644482295-0.717116013986573"


--mixed-Cpanel::Email::Object-20715-1644482295-0.717116013986573

Content-Type: multipart/alternative; boundary="alternative-Cpanel::Email::Object-20715-1644482295-0.0134575859800776"


--alternative-Cpanel::Email::Object-20715-1644482295-0.0134575859800776

Content-Type: text/plain; charset=utf-8

Content-Transfer-Encoding: quoted-printable


The backup process on =E2=80=9Cserver.myserver.com=E2=80=9D completed.


The system started a separate transport process for remote backup destinati=

ons. When the transport completes, the system will send an additional notif=

ication with the status of the transport if any errors were encountered.


Review the attached log =E2=80=9C/usr/local/cpanel/logs/cpbackup/1644482042=

.log=E2=80=9D for further details.


[2022-02-10 00:38:07 -0800] homefiles is: 16162

[2022-02-10 00:38:07 -0800]

[2022-02-10 00:38:07 -0800] mysqlsize is: 14196736

[2022-02-10 00:38:07 -0800] pkgacct completed

[2022-02-10 00:38:07 -0800] info [backup] Successfully backed up account =


etc...

Any ideas would be appreciated. Thank you!

 

[Avensen]

Hello, I'd suggest to:

1. check if server.myserver.com has a strict ("-all") SPF record and the SPF record includes the IP address of your mail server: SPF Check & SPF Lookup - Sender Policy Framework (SPF) - MxToolBox

2. check if server.myserver.com has a DKIM record (use "default" selector): DKIM Check- DomainKeys Identified Mail (DKIM) Record Lookup - MxToolBox

3. check if server.myserver.com has a strict ("p=reject") DMARC record: DMARC Check Tool - Domain Message Authentication Reporting & Conformance Lookup - MxToolBox

4. check if the IP address of the mail server has a correct reverse DNS record (it should point to server.myserver.com): Reverse IP Lookup - MxToolbox

5. check the IP address of the mail server against DNS based email blacklists: Email Blacklist Check - IP Blacklist Check - See if your server is blacklisted

6. check server.myserver.com domain name against DNS based email blacklists: Email Blacklist Check - IP Blacklist Check - See if your server is blacklisted

 

[quietFinn]

Might help if you use Google's Postmaster Tools:

Get started with Postmaster Tools - Gmail Help

You can use Postmaster Tools to track data on large volumes of emails sent and find data about your sending domain. You can view different dashboards to understand details like Gmail delivery errors,

support.google.com

 

[cPRex]

Those are some good suggestions from @Avensen and @quietFinn. I did some testing on my end and couldn't reproduce this when sending a server notification to Gmail, so if you continue to run into problems we may need access to the actual machine experiencing the bounce.

 

[kgs]

Thank you @Avensen and @quietFinn I appreciate your replies.

I have done all those things, but still no joy. I think I'm going to stop the system from sending to gmail for a while and try again at a later date.

 

[Avensen]

Learn and Test DMARC was also recommended to troubleshoot SPF, DKIM, DMARC.

 

[kgs]

Thank you, @Avensen . Yes. I did that too.

 

[Spirogg]

Have you checked your spam folder. In gmail. It has happened before to me long time ago. Everything is setup ok in cPanel.
And I had about 40 in spam. While there I marked them as safe. All of them and it started working again.

 

[kgs]

Thank you, @Spirogg yes, I checked the spam folder. But these were bounced messages. They were refused by gmail.

 

[Spirogg]

Thank you, @Spirogg yes, I checked the spam folder. But these were bounced messages. They were refused by gmail.

just a thought, can you try to whitelist in Gmail account the email from where Cpanel send the alerts?

if you white list it then it may allow it to go through.. I think there might be an option in gmail settings ?

worth a try

 

[Spirogg]

try this:

go to gmail account on your desktop,
then click on the settings cog top right,
then select show all settings
then on the 5th tab on top it says ( filters and blocked addresses)

see if your cPanel email address is showing here.
it should show you a list of emails that are marked as spam and to the right it will say unblock.

if your cPanel addresses is there you can unblock it.


PS sorry I just checked gmail there is no whitelist.. so maybe your email might be in the filters and blocked addresses ??

sorry just trying to help

 

[kgs]

Thank you @Spirogg . I already had the necessary addresses in my contacts and unblocked. As I said, the messages were being refused by gmail. They weren't even getting the chance to be filtered to spam.

 

[Spirogg]

Thank you @Spirogg . I already had the necessary addresses in my contacts and unblocked. As I said, the messages were being refused by gmail. They weren't even getting the chance to be filtered to spam.

Yes. Unfortunately. Wish I could find a solution for you. Please update here if you do.
Have a great day.
Kind regards
SPIRO

 

[Spirogg]

@kgs there is this setting in Exim Configuration tweak settings, not sure if you want to give this a try and see if this might solve your issue with gmail. maybe not but just a try


Enable Sender Rewriting Scheme (SRS) Support [?]
This option rewrites sender addresses so that the email appears to come from the forwarding mail server. This allows forwarded email to pass an SPF check on the receiving server.