3570776 - SCC email alerts not being received - Mail server issue

Customer tries to add an email list to the Cloud connector´s alert notification, but the emails are being delivered to all emails in the list or just some emails are not receiving.  

In the Cloud connector´s logs we can see the logs message showing: 

2025-02-12 14:11:10,906 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #trying to connect to host "10.1.1.1", port 25, isSSL false
2025-02-12 14:11:10,978 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #connected to host "10.1.1.1.", port: 25
2025-02-12 14:11:11,012 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #Found extension "SIZE", arg "104857600"
2025-02-12 14:11:11,013 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #Found extension "PIPELINING", arg ""
2025-02-12 14:11:11,013 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #Found extension "DSN", arg ""
2025-02-12 14:11:11,014 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #Found extension "ENHANCEDSTATUSCODES", arg ""
2025-02-12 14:11:11,014 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #Found extension "STARTTLS", arg ""
2025-02-12 14:11:11,014 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #Found extension "8BITMIME", arg ""
2025-02-12 14:11:11,014 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #Found extension "BINARYMIME", arg ""
2025-02-12 14:11:11,014 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #Found extension "CHUNKING", arg ""
2025-02-12 14:11:11,014 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #Found extension "SMTPUTF8", arg ""
2025-02-12 14:11:11,015 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #use8bit false
2025-02-12 14:11:11,160 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #Verified Addresses
2025-02-12 14:11:11,160 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #  xxxxx@sap.com
2025-02-12 14:11:11,161 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #  xxxxx@sap.com
2025-02-12 14:11:11,161 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #  xxxxx@sap.com
2025-02-12 14:11:17,270 +0000#DEBUG#com.sun.mail.smtp#https-jsse-nio2-8443-exec-2#          #message successfully delivered to mail server

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Cloud connector

mail, not delivered, alert, notification, sending alerts, smtp, message, mail server, anti-spam , KBA , BC-MID-SCC , SAP Cloud Connector On-Demand/On-Premise Connectivity , Problem