SPF records can be queried using the nslookup command.
Method:
The type of the query is txt(SPF records are all txt files). The command is:
nslookup -q=txt domain name
1.If the email address is a***@example.net, the domain name to be queried is example.net. As shown in the screenshot, you can see that the example.net SPF record is included in the spf.sg.aliyun.com txt type by include this keyword in the result.
2.spf.sg.aliyun.com querying again, the final result shows all trusted IP addresses.
If you have other sending IP addresses, you can add the record value to the SPF resolution in the form of v=spf1 IP4:IP address include:spf.sg.aliyun.com -all
. Pls make sure that the IP address is a trusted IP address. If it is a shared IP address, there is a risk of being counterfeit.