This PR works as expected.

A few changes...

1 - I would create a separate section called Auto Reply. It would look more elegant, in addition, there is an enable/disable option. See bellow

BEFORE

AFTER

2 - One of the email templates must be identified and used for the auto reply, because messages sent to visitors have a default format (logo, ...). On this occasion, the contact template that the store receives should also be changed. It is ugly, a relic from the past. Of course, in other PR.

3 - The subject must be set as Contact Form Confirmation.

4 - The message in the body must be polite. E.g. "Thank you for contacting us. We will reply you shortly. Have a nice day."

@ADDISON74 I should have fixed all of your notes, from my tests the PR works as intended. I didn't work on point n.2 because I think it's a big topic for another PR (or more).

Since I changed a lot of stuff here, although I tested it, I won't put my green check on this, at the moment, and wait for other reviewers.

I think this needs a warning on the setting that an activated one can be used to spam email addresses.

maybe something for a future iteration(does not need to be part of this PR) a setting to limit it to logged in users, and making sure only the account email is used as sender

@Flyingmana very nice catch, I've added a warning message, which is absolutely necessary. At a later time we could enable ratelimiting for the contact us form.

Please ignore my green stamp. I chose something else after making the comment in the code. I will check the new changes, at first glance they are fine.

@fballiano - Did you make the change for point 1 as well?

@fballiano - Did you make the change for point 1 as well?

yep

The warning message does not resemble what already exists through the Backend. I will make you a proposal.

The first word Warning should be in red.

I don't think it's possible to have html in that message (make it red)

Html is possible, it needs to be wrapped into <![CDATA[]]>

For example check this file /app/code/core/Mage/Checkout/etc/system.xml

Html is possible, it needs to be wrapped into <![CDATA[]]>

For example check this file /app/code/core/Mage/Checkout/etc/system.xml

you live you learn :-D

The warning message does not resemble what already exists through the Backend. I will make you a proposal.

I'll wait for this

retested, works ok