can this be done? only receiving emails from one domain and that is all, only for internal use in between the company, so only emails form siteA.com and siteB.com
So if you host the box online then probably not.
If the box is hosted inside your company and there is a site-to-site vpn then you could in fact have a private email system that nobody can access from outside the box.
I don’t think this would be very ideal though…
both site are hosted on 2 different VPS, this is was before I was explained what needed to be done, both mail servers are up and running but company wants to put restriction to only receive emails between both site. is there a whitelist option in mail-in-a-box?
No, but you can block port 25 with the exception of the other mail server’s IP.
Maybe this is what your looking for?
Again modifying config files will definitely revert if there is an upgrade done to MiaB.
thanks for the information, I will read
yes it did help so what I did was configure the /etc/postfix/main.cf
smtpd_sender_restrictions=check_sender_access hash:/etc/postfix/allowed_senders,reject
smtpd_recipient_restrictions=check_recipient_access hash:/etc/postfix/whitelist,reject
allowed_senders help me block my users from sending any mail external unless is the domain name in the file ex:
thisdomain.com OK
mydomain.com OK
only these 2 site would be on the filter to send emails
the whitelist allow only emails from the two site above to receive but anything that comes from any other source would be blocked.
as always adding this changing run the command postmap and the location of the files.
appreaciate the help, hope this works for someone else