Exchange DKIM

Check instruction from Microsoft site

Exchange 2016/2019: Implementing DKIM – TechNet Articles – United States (English) – TechNet Wiki (

Note DKIM string for Internal Windows DNS

– The suggested DNS record is longer than 255 characters
– Windows DNS txt record will cut out if one line of characters is longer than 255
– Start from V=DKIM1;k=rsa;……up to 255th character, press enter so the rest will go to second line, that way after create record no original string is missing