Hi,

I have here a root server with Plesk. There are some domains with inboxes for family emails and some mini-projects (IPS). Does somebody know what is really needed for the mail server/domains to be sure that all mails are delivered and no misusage through spammer is possible at the same time?

Thanks,
Sonya

All of them.

Dmarc is essentially a way to tell mail providers that they can block any email from your domain that doesn't have a valid SPF or dkim. So that sits on top at the end and is a failsafe against your emails being spoofed.

SPF and dkim are also used by email providers and isp's for their internal spam checking. So, for the best chance of getting your emails delivered you need to use both.

I recently got asked to help with mail delivery rates at my job. I didn't dive into it too much but having set a DKIM key set in your domain entries is perhaps the most important thing. I would love to hear on that subject more myself.

I have implemented all three. I found it pretty tricky if you are not a server administrator 😞

Another question: are abuse@example.com and postmaster@example.com needed for every domain as well?

I'm finding it tricky to get dkim to work using whm/cpanel and cloudflare. Copied the dns settngs, removed quotes, but still not recognized.

Send a test mail from ACP to https://dkimvalidator.com/ and see how your mail is validated. Does outgoing mail contain DKIM signature? What is the selector.example.com that validator is looking to compare? 

From what I can tell, godaddy doesn't implement DKIM properly, or at all.  DMARC/SPF is fully functional though, and we haven't had any deliverability issues since configuring it.

Websites we found particularly helpful were https://mxtoolbox.com/ (paid subscription) and https://www.mail-tester.com/ (free)