How to respond automatically to received emails?

Hello

do you know how I can automatically reply to received emails?

Let's say that someone sent me an email: "Hello, I'm interested in your services" and I want to automatically reply to his email with more info.

I've seen some people do this, but I have no idea what software they are using. Thanks in advance!

Depending on what email service you using it's either called "autoresponder" or "vacation" mode.

What ESP you using?

Using Mozilla Thunderbird, this method works like a charm: https://support.mozilla.org/en-US/questions/1126211
You just have to google email auto reply + your service provider or mail client.

you will use phpmailer function for auto responding otherwise you have an option in cpanel for auto responding for received ones