fix(errors): normalized error categories

Author: andris9

lib/format-address.js

@@ -20,7 +20,7 @@ function formatAddress(delivery) {
             // the result does not seem to be either IPv4 or IPv6 address
             let error = new Error(delivery.decodedDomain + ' does not appear to be a properly formatted IP address');
             error.response = `DNS Error: ${error.message}`;
-            error.category = 'compliancy';
+            error.category = 'dns';
             return Promise.reject(error);
         }
         if (net.isIPv6(delivery.decodedDomain) && dnsOptions.ignoreIPv6) {

lib/get-connection.js

@@ -57,7 +57,7 @@ function getConnection(delivery) {
                 } else {
                     error = new Error(`Connection to the Mail Exchange (MX) server of "${delivery.domain}" failed`);
                     error.response = `Netowrk error: ${error.message}`;
-                    error.category = 'connect';
+                    error.category = 'network';
                     error.temporary = true;
                 }
                 return reject(error);