Bind9: Define long TXT records for DKIM keys

Publication date: 2023-10-11

Issue: Long TXT records for DKIM fail to load in Bind9

Bind9 refuses to start with TXT records that exceed a string length of 255 characters. However, for DKIM keys this length is not sufficient.

Solution: Split the record into substrings

The long string may be split into several parts that don't exceed the maximum length of a single record. This can be done on the same line by just inserting additional quotes in between like this:

selector._domainkey IN 3600 TXT "v=DKIM1;part1" "part2" "part3"

Hint towards the solution

The problem is discussed in a forum where multiple users contributed information: https://serverfault.com/questions/571720/publishing-long-domain-key-records-in-bind9