Use email worker for autoresponder on email routing

I use email rotuing for my very small domain (3 emails per week, a comunity service with almost a zero budget so - i eate all free tiers i could have).
I setup a [email protected] (on CF email rouging) → free gmail account (15 GB free) it works. I do need a working autoresponder like “your email is important to us”.

CF adds an envelope to every email (and, well it does it by the book, state of art and every piece of RFC is respected), unfortunatly in GSutie - autoresponder reponds to evenlope email - like

(if i simply go with respond on gmail it does fine, it’s only with autoresponders).

So - the real chalange is email worker able to do a autoresponder (my Gmail smtp is ready ! and also i have a free tier other smtp service to sent my emails, so i don’t want CF to be SMTP - simply add some static text - ‘your email is realy important to us, please be paitent’ and - use - other smtp to do autoresponse).
And still - forward mail to Gmail as it does already.

Any hints?

Came here looking for a solution to exactly the same problem.

Gsuite replies to the envelope which doesn’t work, so trying to find a way to create a worker to:

  1. send an autoreply
  2. forward the mail

As now, simply this is not posible as straight forward task.
There were email vendors with free plans that with many, many hacks allowed for that, but it’s not posible right now.
In other words i do not know a free solution for that funcion right now, nor - any resarch or asking on workers on CF’s discord - simply this is not possible.
I’ve found wery cheap (still not free of charge) VPS, that - i fetchmail from gsuite, use formail - to extract headers and use - (freetier, not payd) “getresponse” subscription plan (up to 500 emails / month) to send email (as my VPS has no public, direct IPv4 that i could use for maiilng - it’s a very cheap VPS with limited resources).

As - i looked for simple, non-profit organisation with less that 50 e-mails in a month - i stick with this. Well sending email is - to have a public ip and watch for it’s reputation so i understand why CF or Gsiute does not to allow for modyfining headers.

But i don’t understand why is not possible do make a such worker (email workers simply can’t do it).