Contact Closure Email Generator - Email Server


I’m trying and failing to use this product, and I’m hoping there’s something I’m missing. All the major email providers have discontinued the use of Username+Password authentication, so I’ve been trying to set this up to send via a self hosted email server.
Dead simple server, port 25 on the same network, no authentication required, and when I trigger the contact I get this in the logs.

[E][ssl_client32.cpp:63] handle_error(): SSL - An invalid SSL record was received
[E][ssl_client32.cpp:65] handle_error(): MbedTLS message code: -29184
[E][WiFiClientSecureESP32.cpp:179] connect(): start_ssl_client: -29184
Error sending Email, could not connect to server
Email failed with status: 3

I know the SMTP server is working because I can connect to it via telnet and it responds correctly.

I’ve already flashed the ESP32 chip with the newest code available via the Github Python script, which didn’t change anything.


So I made a video a few days ago about using App Passwords for gmail. This should solve your problem: Embedded Email using Gmail App Password - YouTube

As far as your local email server, it sounds like you’re trying to use a secure connection to a server and the server doesn’t have SSL enabled correctly. This isn’t within our support wheelhouse, but generally getting SSL keys for HTTPS/SSL is tricky on an IP address. I think you’ll have to use a snake oil key or there might be a new option using letsencrypt.

Is it possible to use this without SSL? I have no need for it as the data isn’t sensitive, and doesn’t need encryption.

No we do not support SMTP Email Brokers without SSL.

Okay, I’ve gone through and created the Gmail account + App password. After setting that all up, I now get the following. I tried sending the email both to it’s own account, and to a company address, and got the same error both times. I can see the traffic leaving our network, and it’s not being blocked by any firewall.

I’ve also tested with both ports Gmail has used - 587 and 465

Input 1 opened
emailBuffer updated to: [“{"subject":"Input 1","body":"Closed","recipients":[""]}”,“{"subject":"Input 1","body":"Opened","recipients":[""]}”]Error sending Email, set recipient failed
Email failed with status: 3

Edit: I’ve now also tested this account using Outlook on the same network with the same server info and credentials, which worked just fine.