Email Routing and Vacation responders

I have noticed that I am having an issue with the Gmail Vacation Responder. I was wondering if anyone had noticed the same issues.

First - for diagnostic purposes - my configuration is as follows:

  1. Mail for my domain ( arrives via the Cloudflare mail exchangers linda, amir and isaac.
  2. The mail in question is forwarded to a Gmail account
  3. Outbound mail is done via a 3rd party SMTP - which I do not think is involved in this situation.

As a summary, the problem I am having is that automatically generated messages from Google’s Vacation Responder function are being sent to addresses that look like [email protected] instead of going to [email protected] (a fake address for this post - but you get the idea)

When I look through the headers, the only relevant ones that I see having anything like cfbounces in it are:
Return-Path: [email protected]
smtp.mailfrom="[email protected]";
dmarc=pass (p=REJECT sp=REJECT dis=NONE)
Received-SPF: pass ( domain of [email protected] designates as permitted sender) client-ip=;

I have to imagine that it is the “Return-Path” header that is causing the Gmail vacation response to go to the wrong place.

I would like to know if this is working as intended, if something different should be put in the Return-Path header, or if there is a different header that should be set by the Cloudflare mail routing service to help these vacation responses work.

Right now, I am concerned that when people turn on the vacation responder (other than the message not being delivered) that Cloudflare would start tracking these vacation responders as failure bounces that would ultimately get my email addresses listed on a suppression list.

Thank you.