Vacation response to Gmail is not being delivered

I have a problem with vacation messages not being delivered to Gmail.
We have a domain set up with spf, dkim enabled, normal messages work fine.
But when e-mail is being sent from Gmail, and there is an autoresponder enabled, the sender does not get the autoresponse message. Also no bounce, our server says the message is delivered like normal.

I've tested multiple e-mail providers, and the Vacation message itself definitely works, it's also set up to respond every time.
I have a big suspicion that this may be due to the fact that vacation messages in our CWP7 pro server are enveloped from vacation@servername.com and not the mailbox of the client (it uses the server name and not the domain name).
The return path is also the vacation@servername.com not mailbox@domain.com.

Is there a way to change the vacation message sender to the original mailbox?

If you think I am approaching this issue from the wrong direction please comment.

Where do you have the vacation message setup?

In RoundCube?
If so, What version are you running?
If so, that should be sending form the mailbox it is setup in.

Ok so I think I found out exactly what happened.

Note that the domain before yesterday did not have DKIM (only SPF).
It seems that when the vacation mailer is sending its mail, it uses it's own SPF record and not the SPF record of that domain.
Because we had not set up SPF for servername.domain.com, there was no DKIM and no SPF set-up which made the email  unauthenticated.

Before configuring DKIM I was meddling with various test mailboxes and I had left the option to send only once per day. So the vacation mail was initially sent when there was no DKIM and after DKIM was configured it did not send because it was checked to send once per day.

P.S. Changing the from address in autoresponder settings still sends emails enveloped from vacation@servername.com, but with DKIM and correct SPF there are no problems.

Didn't ask about DKIM, since your initial post said:

We have a domain set up with spf, dkim enabled, normal messages work fine.

But glad you got it figured out and it's working.