Email server for Alarm system

[Kuscher]

Good morning, I hope someone can assist me.

On or about 25/26 May 2022 , I believe Ziggo made a change in its email protocols as my alarm system no longer can send emails and gives a communication fault.  I believe possibly a tightening of procedures that required a email and password to use the email server?

The alarm system, which is a professional one, only allows email addresses and the address of the server, no current option to enter a password. All worked well up to 26th May 2022, but since then I believe there is a change that stops using either mail.ziggo.nl or mail.kpn.nl

Does anyone know what the change was and if there is a work arround ?  I know I am not the only person with this problem

Thank you in advance

[Dave!]

Maybe you mean this change

[tobiastheebe · Accepted solution]

This is likely caused by the SMTP server supporting only TLS 1.2 encrypted connections. Your alarm system appears to connect to port 25 without authentication, this is no longer supported. A workaround does exist, albeit quite complex. Outbound mail would have to be delivered to an SMTP relay first, where it is redirected to the destination SMTP server (in this case, smtp.ziggo.nl) with the required authentication and encryption. I am using Postfix on my Linux server for this purpose.