Configuration and operation   
4.6 Security configuration(CP 1543SP-1) 
  CP 1542SP-1, CP 1542SP-1 IRC, CP 1543SP-1 
86  Operating Instructions, 01/2017, C79000-G8976-C426-03 
 
Security > E-mail configuration 
E-mail configuration 
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As default, the sending of e-mails is disabled. 
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Enable this option if you want to use the sending of unencrypted e-mails via SMTP port 
25. 
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If your e-mail service provider only supports encrypted transfer, enable this option. Select 
the protocol via the port number: 
–  Port no. 587 
When using STARTTLS the CP sends encrypted e-mails. 
–  Port no. 465 
When using SSL/TLS (SMTPS) the CP sends encrypted e-mails. 
Ask your e.mail service provider which option is supported. 
If you want to use an Internet connection with an IPv6 infrastructure, note the information 
in the section IPv6 (Page 43). 
 
Security configuration(CP 1543SP-1) 
4.6.1
 
 
VPN (Virtual Private Network) 
VPN tunnel 
Virtual Private Network (VPN) is a technology for secure transportation of confidential data in 
public IP networks, for example the Internet. With VPN, a secure connection (tunnel) is set 
up and operated between two secure IT systems or networks via a non-secure network. 
One of the main features of the VPN tunnel is that it forwards all frames even from protocols 
of higher layers (HTTP, FTP etc.). 
The data traffic between two network components is transported practically unrestricted 
through another network. This allows entire networks to be connected together via a 
neighboring or intermediate network.