@ThomasB
Another info if you use gmail with emailrelay.
My account was switched to second-factor-authentication and now you have to generate an app-specific password that you use with emailrelay (or other third party apps)
https://support.google.com/accounts/answer/185833?hl=en

Setup is quite simple Domain: does not really matter, i tried "locallan" as well Server: IP Adress of my orangepi running emailrelay Sender: my gmail mailaddress Receiver: destination email address Don't know, if this is the correct way, but the mails get delivered. ;) If you use your gmai...

You can try emailrelay instead of exim4. That is what I used some time ago (Could neither get it to work with exim4 ;) I am running it on an orangepi with armbian, should be quite similar on a rpi. Sourcecode: https://sourceforge.net/projects/emailrelay/files/emailrelay/2.2/ Wiki: http://emailrelay....

I will try. Never done that before

Here is the log after a reset by button and the following sleep cycle. I can't see any errors. Interesting is the line with "Restart Reason" On first Boot, it is 39 : Info : INIT : Cold Boot - Restart Reason: CPU0: Vbat power on reset CPU1: for APP CPU, reseted by PRO CPU After Deepsleep, ...

Is there anything special to consider for using deepsleep on the ESP32. Connecting GPIO16 to RST is only for ESP8266 i assume, at least it did not change anything for me. At the moment, the board goes to sleep but it always wakes up with a cold boot, for that reason it always sets the security timer...