telegram2email Node-RED Flow

This Node-RED flow acts as a gateway receiving telegram messages and sending them back as emails.

Use cases

• Send a note/remainder email to yourself through telegram app faster than using email app.
• Send message/email to a friend who is not on telegram yet without loosing time opening e.g. gmail website to compose a new email.
• Send messages from a telegram group to someone who does not have access to a telegram account yet for whatever reason (banning on some countries, friend don't want to install new apps, ...).

Node-RED Flow

What it does and what needs to be improved

Each telegram received message is first classified in a switch node as text message or others, assuming others will be an image or sticker.

In each case a template node formats accordingly the body text of the email as HTML:

• Text template includes "user_first_name: text message".
• Image template includes "user_first_name: caption message", followed by the image itself.

You can adapt those templates to suit your needs.

After that, a compose email function generates the subject of the email (msg.topic) and adds the HTML template to the body of the email (msg.payload). Subject has two variants:

• If the message comes from a private user, the subject is "TG-user_first_name".
• If the message comes from a group chat, the subject is "TG-group_name".

You can adapt the subject to suit your needs.

Finally the output email node sends the email.

Improvements to be done

• Add support for other message types: audio, video, document, voice, ...
• For chat group messages, it would be interesting to generate hourly or daily summary messages for a better reading of the chat conversation in the email app.

Collaboration is very welcome to this project.

Install

First you need to install node-red-contrib-telegrambot library into Node-RED for telegram integration [1].

Then import the flow file "telegram2email.json" to your Nodered server.

Finally, configure nodes with your own data.

Nodes configuration

Configure telegram receiver node with your own bot. You need to enter Bot-Name and Token.
You can create your own bot in telegram sending the /newboot command to @botfather telegram bot.
I changed poll interval to 10000 ms instead of 300 ms as I don't need real time interaction.
See sample configuration in screenshots folder.

Check the template and function nodes if you want to change main text and/or subject of the email.

Configure email output node with your SMTP server details for sending emails [2].
See sample configuration in screenshots folder.

More information:

[1] https://flows.nodered.org/node/node-red-contrib-telegrambot
[2] https://flows.nodered.org/node/node-red-node-email