DNS Tips
https://mxtoolbox.com/DMARCRecordGenerator.aspx
https://www.alitajran.com/configure-dmarc-record-for-office-365/
-------------------DKIM------------------------------
https://mxtoolbox.com/NetworkTools.aspx
https://mxtoolbox.com/dkim.aspx
google._domainkey.easydmarc.us
google._domainkey.urmigroup.neturmigroup.net:google
selector1._domainkey.selbn.comselbn.com:selector1
Show own IP Address Linux
[root@mail ~]# dig +short myip.opendns.com @resolver1.opendns.com
202.22.199.150
DMARC Record Generator
https://easydmarc.com/tools/dmarc-record-generator
DMARK: DNS entry: TXT
Name: _dmarc
Content: v=DMARC1; p=none; rua=mailto:faruq@worldcm.net
OR
v=DMARC1; p=reject; rua=mailto:postmaster@worldcm.net, mailto:dmarc@worldcm.net; pct=100; adkim=s; aspf=s
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C:\Users\FaruQ>nslookupDefault Server: UnKnownAddress: 156.154.70.22> set type=a> selex01.worldcm.netServer: UnKnownAddress: 156.154.70.22
Non-authoritative answer:Name: selex01.worldcm.netAddress: 115.129.47.195
> selex02.worldcm.netServer: UnKnownAddress: 156.154.70.22
Non-authoritative answer:Name: selex02.worldcm.netAddress: 275.229.247.194
> set type=mx> worldcm.netServer: UnKnownAddress: 156.154.70.22
Non-authoritative answer:worldcm.net MX preference = 10, mail exchanger = spam.metro.net.bdworldcm.net MX preference = 0, mail exchanger = selbn-com.mail.protection.outlook.com> set type=txt> worldcm.netServer: UnKnownAddress: 156.154.70.22
Non-authoritative answer:worldcm.net text =
"v=spf1 include:spf.protection.outlook.com -all">