For increase reputation of email server, we could adding SPF records on public DNS.
What is SPF record?
as information from this link : https://support.google.com/a/answer/33786?hl=en, an SPF record is a type of Domain Name Service (DNS) record that identifies which mail servers are permitted to send email on behalf of your domain. The purpose of an SPF record is to prevent spammers from sending messages with forged From addresses at your domain. Recipients can refer to the SPF record to determine whether a message purporting to be from your domain comes from an authorized mail server.
How to configure SPF records?
On this section, i will configure SPF records on my public DNS using cPanel. Fill of spf records is using TXT records like the following example :
imanudin.net IN TXT "v=spf1 a mx ip4:18.104.22.168 include:mail.imanudin.net -all"
Domain imanudin.net could be sent from all A records,MX records on DNS and address IP 22.214.171.124 include mail.imanudin.net as permitted sender. Besides, not permitted.
This is the example configuration on cPanel
Select Advanced DNS Zone Editor and adding TXT records for SPF
Please sent email to Gmail and check whether SPF records has been known or not. The following is example that the SPF records has been known on Gmail
If you has been saw mailed-by on Gmail, it’s mean you has been success to configure SPF. If no, usually still waiting for propagation of DNS
The following is example configure SPF records on GIF
Good luck and hopefully useful 😀