DKIM & DMARC for hostname

Hi I have my server hostname as I have on this server which has working SPF,DKIM & DMARC. I tested this using gmail and few other test services by sending mails from various

Now the problem is some mails are sent from which fail DKIM & DMARC. Now the problem is if these mails are a lot then the server's IP get added to SPAM list which I cant afford.

Now how to add DKIM and DMARC for server's hostname and where to do it .



Howdy -- if you don't want email going out as -- you could always set the "myhostname" feature within Postfix to contain the domain name you wish to use as the default.

If you were to edit /etc/postfix/, look for the myhostname option in there. Or if it's not there, you could just add a new line containing it.

You could set it to something like:

myhostname =

After making that change, restart Postfix.

Would that do what you'e after?

No, that would actually break the SPF & DKIM as the rDNS and server's hostname should match the one provided by postfix. for SPF and DKIM to pass rDNS is checked.

One of the options is that you could always change the reverse DNS record, that might be a quick and easy way to resolve it (in combination with the above).

If you don't wish to do that --

We're unfortunately not entirely certain how this works, so we'll have to do some experimenting.

But in Email Messages -> Domainskey Identified Mail, there's an option named "Additional domains to sign for". You could try adding your hostname to that list.

What we don't know, is whether that will use the DKIM key for, or whether you'd need to add a new DNS zone for that particular hostname. But that should be fairly simple to test out.

I found the top level menu item "Email Messages". But it doesn't show up from Webmin's "Search" form for "email" or "messages".

"Email Messages" is just below "System Settings" on the navigation bar on the left.

If you aren't seeing that, is the "Mail for Domain" feature enabled in System Settings -> Features and Plugins?