Try explicit wrapping instead of \n

zones/fudo.org.nix

@@ -128,10 +128,13 @@
     usashi.ipv4-address = "209.177.109.150";
   };
 
-  verbatim-dns-records = [
-    ''
-      mail._domainkey IN TXT ( "v=DKIM1; k=rsa; \n p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuwulTvtxhB2UD1aWmey\nB63gZyhU2wWl8zhkQYePOpOMY0l2Qew6Dw+neYNTa\nEUBRtbeoVHhVwI28/kH8HqRte9mQGyQR4JphW7sr4osuD603cdzJMpptYbr2XPRkOxDmY9iBBS\nNgXjp103TQL8HA/7HlLGUsPWYDxjh94Mbb/KzGfBiVLBc3vUIVXZdn\nlLJa/xzIZAT1NXnT3hRHyt7on+6x+uIQ2FOTvyQvTfAASwJa012LzqxlZXykGE7WnHkNFDeyCiSepr4LroW9+Dt+AYKW\nDu1gvF75jy6enewHse06doJoRkvFq+h1ZIymkFfRacYTK43X2ZOXTMLEOrf5lQIDAQAB" )  ; ----- DKIM key mail for fudo.org''
-  ];
+  verbatim-dns-records = [''
+    mail._domainkey IN TXT ( "v=DKIM1; k=rsa; "
+      "p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuwulTvtxhB2UD1aWmeyB63gZyhU2wWl8zhkQYePOpOMY0l2"
+      "Qew6Dw+neYNTaEUBRtbeoVHhVwI28/kH8HqRte9mQGyQR4JphW7sr4osuD603cdzJMpptYbr2XPRkOxDmY9iBBSNgXjp1"
+      "03TQL8HA/7HlLGUsPWYDxjh94Mbb/KzGfBiVLBc3vUIVXZdnlLJa/xzIZAT1NXnT3hRHyt7on+6x+uIQ2FOTvyQvTfAAS"
+      "wJa012LzqxlZXykGE7WnHkNFDeyCiSepr4LroW9+Dt+AYKWDu1gvF75jy6enewHse06doJoRkvFq+h1ZIymkFfRacYTK4"
+      "3X2ZOXTMLEOrf5lQIDAQAB" )  ; ----- DKIM key mail for fudo.org''];
 
   subdomains = {
     test = {

zones/selby.ca.nix

@@ -9,10 +9,13 @@
     webmail = "webmail.fudo.org.";
   };
 
-  verbatim-dns-records = [
-    ''
-      mail._domainkey IN TXT ( "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA68IHVXbgnu0rqAvsM3mKT9WmlvYM22COWh5FzlFOUguZ3nWCrcZGt8l5G004tDjCwgdCz4e0eUq3VqtPIcGfMd56jK61XAqN7wzRXTjEjiaGSENjBX+geoUM+DIS84jeZOFtB7Sm1kqMKfkEarygtNTtibqvFzk34vREVhwcgF3bTl5BjhU9D+7lWwt6VBKCUvMFcJPCHuuM/jMkZb+unllsu8LbtbhWT2TcnHhup/7Yfu4Z79RhdxnL8jbwIPbiCLBkOEbN/624EYHRhtEAPYuQKOjWt1IemQtE6BCxEsHhaSB4W1l1Ji21Q3vDyf0s+LM2ETjT2jxmcYR7G+e10QIDAQAB" )  ; ----- DKIM key mail for selby.ca''
-  ];
+  verbatim-dns-records = [''
+    mail._domainkey IN TXT ( "v=DKIM1; k=rsa; "
+      "p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA68IHVXbgnu0rqAvsM3mKT9WmlvYM22COWh5FzlFOUguZ3n"
+      "WCrcZGt8l5G004tDjCwgdCz4e0eUq3VqtPIcGfMd56jK61XAqN7wzRXTjEjiaGSENjBX+geoUM+DIS84jeZOFtB7Sm1k"
+      "qMKfkEarygtNTtibqvFzk34vREVhwcgF3bTl5BjhU9D+7lWwt6VBKCUvMFcJPCHuuM/jMkZb+unllsu8LbtbhWT2TcnH"
+      "hup/7Yfu4Z79RhdxnL8jbwIPbiCLBkOEbN/624EYHRhtEAPYuQKOjWt1IemQtE6BCxEsHhaSB4W1l1Ji21Q3vDyf0s+L"
+      "M2ETjT2jxmcYR7G+e10QIDAQAB" )  ; ----- DKIM key mail for selby.ca''];
 
   srv-records.tcp = {
     http = [{