The socket read and write code is working. I started looking at what would be needed to implement TLS, before I start on the SMTP code.

Using TLS will need a couple of certificate handling commands to be implemented, and needs date and time in the seconds past 1/1/1970 format. The actual open command for a TLS socket just requires adding an s to the AT+S.SOCKON command. At least I will not have to rip up or re-implement a big chunk of code for it.

When I did the first pass on the clock/calendar code, I ignored the Day of Week value. It turns out that the date string in an outgoing email wants the day of the week value, so I wrote code to calculate that. It was pretty similar to the code to calculate the number of seconds since the epoch.

Several additional values were needed to store in the NVM/configuration structure, so those got added to the NVM code.

I have taken a couple of diversions from this project, as it is a significant project, but it is making progress.