Send email by smtp over smtp-relay.gmail.com TLS from wr21

HI,

i am trying to configure smtp on my digi wr21. Server require tls to be enabled on client side.
How to do it?

i am getting this on my wr21 when it’s try to send email.

08:57:33, 08 Aug 2018,SMTP err 550 5.7.1 https://support.google.com/a/answer/6140680#inval,Bad Response From Remote
08:57:32, 08 Aug 2018,SMTP req by CMD email event.eml
08:57:32, 08 Aug 2018,PPP 1 up
08:57:29, 08 Aug 2018,PPP 1 Start IPCP
08:57:29, 08 Aug 2018,PPP 1 Start AUTHENTICATE
08:57:29, 08 Aug 2018,PPP 1 Start LCP
08:57:29, 08 Aug 2018,PPP 1 Start

regards

Does somebody have some suggestions?