Band steering was disabled
IGMP Snooping- don’t remember seeing this setting
Multicast- don’t remember any related settings

I will set the arcadyan up again tonight and go through all the settings, this router does have a basic gui though and I only used it because it was free.

I have set up the other Technicolor in the shed and everything is working great now, there must be something about the Arcadyan LH1000 that the ESP doesnt like.

The shed router is a Arcadyan LH1000, the house router (working one) is a Technicolor DJA0231 (both look identical). The settings are pretty limited as they are just ISP supplied routers, although I have gained root access to the Technicolor and can tinker with it if needed. I set both esp32 to forc...

Wow, I think that fixed it.
I swapped the two esp32 modules over to the other wifi router and now they have sent 20 emails each without fail. I think I will throw my router I have out in the shed in the bin and replace it with something decent.
Thanks for all your input/help guys, much appreciated.

Ok, I sent 5 successfull test emails from the esp8266 then 2 unsuccessful emails from the esp32. I then sent another 5 successful emails from the esp8266. I checked eco mode and it is turned off. I will try and set up a hmail server this weekend and do some testing. One other thing I just thought of...

Some aditional info I just discovered, if I reboot the ESP32 it successfully sends test emails but after being up a few minutes all test emails fail again.

The email settings from one of my working ESP8266 modules
The email settings from one of the non working ESP32 module, the only difference between the two is I have different subject lines.

I am hoping someone can help me with the email notification on 2 ESP32 modules I have recently set up. Previously I have set up email notification on multiple esp8266 and they work perfectly, but using the same email settings from the esp8266 on the esp32 and it fails when sending a test email (see ...