Setting Auto Responder - Failed

Hey

Virtualmin seems to have problems in creating a autoreply.
When trying to set one i get the error: Failed to save user : Failed to open /home/domain/autoreply-user.domain.txt.webmintmp.28399 : Permission denied
Evrytime when i try the number changes.

The rule does get added to /etc/aliases, but whit out the webmintm part.
When i check if the file exists, its not there. I have created the file and set permissions ( from root to domain, as the other files have the same rights)
but alas, still the same error.
I conclude from this that it wont change or create the files needed.

The autoreplay function itself does work, but it can’t locate the file. (as i removed it again)

I think its a permission thingy… but where?

What i like to know is:

What do i have to fix so it will create the file?

Can i change the path it wants to have? (like: /home/domain/mailrules)

Whats the meaning of the "webmintmp.number ?

System info

Os- CentOS 7.3

Virtualmin - 5.07

10Gb Mem

4 cores

I found a old topic here: https://www.virtualmin.com/node/12310, but no sollution in it