My environment: hMailServer 5.6.8 on Windows Server 2022 Standard
Let's say I have two domains (I don't really own these domains, they're just examples), www.myblog.com and www.mailserver.com. They are both hosted on the same machine and have the same IP address 1.2.3.4.
The blog site www.myblog.com uses www.mailserver.com to send emails. The site www.mailserver.com only serves as a mail server; it is not accessible from a browser. I have set it up so that when www.myblog.com sends an email to someone, the recipient's email server receives SENT: EHLO www.mailserver.com, but sees SENT: MAIL FROM:<[email protected]> message, so the recipient sees that the email came from myblog.com.
Everything is working fine so far. Recently I decided to check the "spam rating" of my setup at 
The DNS records for each domain are as follows (note the PTR record for 1.2.3.4):
IP address 1.2.3.4
PTR www.mailserver.com
www.myblog.com
Name Type Value
@ A 1.2.3.4
* A 1.2.3.4
@ MX 10 myblog.com.
@ TXT v=spf1 ip4:1.2.3.4 ~all
dkim._domainkey TXT v=DKIM1; t=s; k=rsa; p=[super long public key string]
www.mailserver.com
Name Type Value
@ A 1.2.3.4
* A 1.2.3.4
@ MX 10 mailserver.com.
@ TXT v=spf1 ip4:1.2.3.4 ~all
CodePudding user response:
I was able to get rid of the warning by adding an extra TXT record with the name "www" to the www.mailserver.com DNS:
www.mailserver.com
Name Type Value
@ A 1.2.3.4
* A 1.2.3.4
@ MX 10 mailserver.com.
@ TXT v=spf1 ip4:1.2.3.4 ~all
www TXT v=spf1 ip4:1.2.3.4 ~all <-- adding this record fixed the warning
