Properly configure DKIM and DMARC settings

I have two servers - 1 is for web pages, the other is for email. So, [login to view URL] web pages display on one server. Mail sent to and from info@[login to view URL] is handled by another server. The settings are mostly correct. Emails have been working fine for a couple of years, but I am not sure that DKIM settings are correct. Sometimes email is rejected. Also, I have no DMARC or rDNS set up. I want: 1) Settings for all 3 corrected 2) Instructions on how to set future email accounts correctly Linux server and VPN cPanel I have access to both servers Here is the support message from the server admin, which further explains: This test shows a good score but you should setup a DMARC record A DMARC policy allows a sender to indicate that their emails are protected by SPF and/or DKIM, and give instruction if neither of those authentication methods passes. Please be sure you have a DKIM and SPF set before using DMARC. You do not have a DMARC record, please add a TXT record to your domain [login to view URL] with the following value: v=DMARC1; p=none Verification details: [login to view URL]; dkim=pass (2048-bit key; unprotected) header.d=[login to view URL] header.i=@[login to view URL] header.b=FVz6huf8; dkim-atps=neutral [login to view URL]; dmarc=none header.from=[login to view URL] [login to view URL]; dkim=pass (2048-bit key; unprotected) header.d=[login to view URL] header.i=@[login to view URL] header.b=FVz6huf8; dkim-atps=neutral From Domain: [login to view URL] DKIM Domain: [login to view URL] Your reverse DNS does not match with your sending domain. Reverse DNS lookup or reverse DNS resolution (rDNS) is the determination of a domain name that is associated with a given IP address. Some companies such as AOL will reject any message sent from a server without rDNS, so you must ensure that you have one. You cannot associate more than one domain name with a single IP address. Your IP address [login to view URL] is associated with the domain vps.mtandt.com. Nevertheless your message appears to be sent from server.thresholdweb.net. You may want to change your pointer (PTR type) DNS record and the host name of your server to the same value. Here are the tested values for this check: IP: [login to view URL] HELO: [login to view URL] rDNS: [login to view URL] Thanks