Try to use other mail server.

strato-production.yaml

@@ -59,9 +59,9 @@
 
         - name: Send Email
           community.general.mail:
-            host: smtp.vodafonemail.de
+            host: mail.steinle-computer.de
             port: 465
-            username: christiansteinle@arcor.de
+            username: kontakt@steinle-computer.de
             password: "{{ mail_password }}"
             to: "{{ item.value.email }}"
             subject: Datenbank Backup