[PROD] Bouncing emails

[szabozoltan69]

Issue

Some outgoing emails are bounced.
It turned out that our SpamScore is generated mainly from these aspects:

1.8 point:
HTML_IMAGE_ONLY_08 BODY: HTML: images with 400-800 bytes of words

0.6 point:
HTML_MIME_NO_HTML_TAG HTML-only message, but there is no HTML tag

Lets check our notifications' template to get rid of these accusations.

[tovari]

Interestingly, it doesn't happen to all users. The above message was sent to an ifrc.org email, but it doesn't happen to all ifrc.org email holder.

[tovari]

    "CreatedDate": "2024-11-26T03:11:58.2624289",
    "SpamReport": " pts rule                      description                                       
---- ----------------------    --------------------------------------------------
0.0 URIBL_DBL_BLOCKED_OPENDNS ADMINISTRATOR NOTICE: The query to                
                               dbl.spamhaus.org was blocked due to usage of an   
                               open resolver. See                                
                               https://www.spamhaus.org/returnc/pub/ [URIs:      
                               ifrc.org]                                         
0.0 URIBL_BLOCKED             ADMINISTRATOR NOTICE: The query to URIBL was      
                               blocked.  See                                     
                               http://wiki.apache.org/spamassassin/DnsBlocklists…
                               #dnsbl-block for more information. [URIs:         
                               ifrc.org]                                         
0.0 URIBL_ZEN_BLOCKED_OPENDNS ADMINISTRATOR NOTICE: The query to                
                               zen.spamhaus.org was blocked due to usage of an   
                               open resolver. See                                
                               https://www.spamhaus.org/returnc/pub/ [URIs:      
                               ifrc.org]                                         
0.0 NO_RELAYS                 Informational: message was not relayed via SMTP   
0.1 MIME_HTML_ONLY            BODY: Message only has text/html MIME parts       
1.8 HTML_IMAGE_ONLY_08        BODY: HTML: images with 400-800 bytes of words    
0.0 HTML_MESSAGE              BODY: HTML included in message                    
0.6 HTML_MIME_NO_HTML_TAG     HTML-only message, but there is no HTML tag       
0.1 HTML_SHORT_LINK_IMG_1     HTML is very short with a linked image            
0.0 NO_RECEIVED               Informational: message has no Received headers    
0.1 MISSING_MID               Missing Message-Id: header                        ",
    "SpamScore": 2.80,

[tovari]

from https://check.spamhaus.org/returnc/pub:

If you are viewing this page, you have likely sent an email that was not delivered to the recipient. In the resulting bounced email message you have found and clicked this link: https://check.spamhaus.org/returnc/pub/

The problem doesn’t relate to your email set-up.

Why has my email not been delivered?

• The problem is with the recipient’s email server configuration.
• This is not due to an issue with your email set-up.
• It is not because you are listed on one of our blocklists.

What do I need to do next?
If the email is urgent or essential:

• Call the recipient and tell them that they have an issue with receiving emails.
• Ask the recipient to urgently contact their email server administrator. This page provides the information required to correct this issue: Using our public mirrors? Check your return codes now.
  .....