Make a record and MX record for your domain name, and set the MX record set for you in the mail system of the server. Resolve the IP address of your server to your MX record!
Set the domain name SPF record. SPF is a DNS record type proposed to prevent spam. It is a TXT record, it is used to register all IP addresses owned by a domain name for external mail.
Domestic Network: V = spf1 a MX ip4: 184.108.40.206/25 include: aspmx.googlemail.com ~ All
Intranet: V = spf1 mx ~ All
View domain name with SPF record URL: http://www.kitterman.com/spf/validate.html
SPF is a DNS-related technology. Its content is written in the TXT record of DNS. The MX record is used to indicate to the sender the mail server of a domain name. SPF is opposite to MX. It indicates to the recipient which email servers will send emails after a domain name is approved.
From the definition, we can see that SPF is mainly used for anti-spam, mainly for spam emails with spoofed domain names of senders.
For example: When the coremail mail server receives a self-claimed sender is a firstname.lastname@example.org mail, then in the end it is really sent from the gmail.com mail server? Then we can query the SPF record of gmail.com
So how should we create it? Go to domain name management, and create a TXT record in domain name resolution and enter the correct SPF data to take effect. (Not all domain name registrars support TXT records. Please ask if your domain name registrar can add multiple TXT records !!!)
The record format varies depending on the DNS status of each domain name. However, the record format is as follows:
V = spf1 [[pre] type [ext]... [mod]
Format you may not understand, it does not matter, you can generate a line of your SPF, URL: http://old.openspf.org/wizard.html
Check whether your server IP address has been blacklisted by international spam organizations. Go to the following websites to check whether your server IP address is in the blacklist of each RBL organization. If your IP address is listed in the blacklist, you need to communicate with them to solve the problem. The solution is complicated and will not be detailed here. If you have this problem, please reply to the list of organizations that have been blacklisted, I will give you an unblocking solution for that organization.
Let's talk about a few big ones:
(1) first, spamhaus.org
The most severe, the most influential to the spamhaus project team, web site http://www.spamhaus.org. As long as it is blacklisted, your email server is paralyzed, because it is said that more than 80% of the servers around the world will reject emails sent from your email server.
(2) second spamcop, website http://www.spamcop.net. Almost all email services in China hit its muzzle.
(3) China's largest http://www.anti-spam.org.cn/
Register your IP address with each ESP
To provide your IP reputation, you can also take the initiative to register your IP address and email system information on the websites of various email service providers, this will greatly reduce the chances for these operators to intercept emails sent from your email system.
You can send emails to the Administration mailbox email@example.com of the Internet Society of China Anti-Spam center to register the correspondence between your mail server IP address and domain name.
Customize the subject and content of your mail. Do not use templates. The mail format of tens of thousands of sites is the same, which is easy to be blocked by the email service provider. The system is defined as spam.
After completing the above steps, your email is basically unobstructed. I wish you all the best!