Hi,
Unfortunately there is no base function for that, but you could try exporting logread output into a file that would be held somewhere in /etc folder of your router.
Use logread > /etc/log.txt
This will save the output in /etc/log.txt and the file should not be gone after the restart.
About sending it through SMS or email - I don't think that would be possible because of the character limit.
You could use this command in the script to send emails through CLI
#!/bin/sh
echo -e "subject:test\nfrom:email@gmail.com\n\ntestestestestest" | sendmail -v -H "exec openssl s_client -quiet -connect smtp.gmail.com:587 -tls1 -starttls smtp" -f email@gmail.com -au"receiver@gmail.com" -ap"lalalal" email@teltonika.lt
EB.