Description:
If the SMTP server requests a certificate for authentication although no certificate is available in the router or access point when using TLS 1.3, the TLS client in LCOS attempts to create a signature with a non-existent certificate. This fails, of course, and leads to a Handshake failure in the TLS negotiation. As a result the authentication with the SMTP server and thus also sending E-Mails is not possible.
This behavior has been fixed in the following firmware versions. Please update the firmware of your device, if necessary.
- LCOS 10.42 SU10 (download latest version)
- LCOS 10.50 RU10 download latest version)
- LCOS 10.72 SU2 download latest version)
Workaround for older firmware versions:
If none of the firmware versions mentioned above is available for the used device, as a workaround TLS 1.3 can be deactivated for sending E-Mails.
Connect to the CLI of the affected device and enter the following command to restrict the protocols to TLSv1, TLSv1.1 and TLSv1.2:
set Setup/Mail/SSL/Versions TLSv1,TLSv1.1,TLSv1.2
