Index: src/OFDNSResolver.m
==================================================================
--- src/OFDNSResolver.m
+++ src/OFDNSResolver.m
@@ -248,11 +248,11 @@
 static OF_KINDOF(OFDNSResourceRecord *)
 createResourceRecord(OFString *name, of_dns_resource_record_class_t recordClass,
     of_dns_resource_record_type_t recordType, uint32_t TTL,
     const unsigned char *buffer, size_t length, size_t i, size_t dataLength)
 {
-	Class class;
+	uint16_t preference;
 	id data;
 
 	if (recordClass == OF_DNS_RESOURCE_RECORD_CLASS_IN) {
 		size_t j;
 
@@ -260,53 +260,95 @@
 		case OF_DNS_RESOURCE_RECORD_TYPE_A:
 			if (dataLength != 4)
 				@throw [OFInvalidServerReplyException
 				    exception];
 
-			class = [OFADNSResourceRecord class];
 			data = [OFString stringWithFormat:
 			    @"%u.%u.%u.%u",
 			    buffer[i], buffer[i + 1],
 			    buffer[i + 2], buffer[i + 3]];
-			break;
+
+			return [[[OFADNSResourceRecord alloc]
+			    initWithName: name
+			     recordClass: recordClass
+			      recordType: recordType
+				    data: data
+				     TTL: TTL] autorelease];
 		case OF_DNS_RESOURCE_RECORD_TYPE_CNAME:
 			j = i;
 
-			class = [OFCNAMEDNSResourceRecord class];
+			data = parseName(buffer, length, &j,
+			    ALLOWED_POINTER_LEVELS);
+
+			if (j != i + dataLength)
+				@throw [OFInvalidServerReplyException
+				    exception];
+
+			return [[[OFCNAMEDNSResourceRecord alloc]
+			    initWithName: name
+			     recordClass: recordClass
+			      recordType: recordType
+				    data: data
+				     TTL: TTL] autorelease];
+		case OF_DNS_RESOURCE_RECORD_TYPE_MX:
+			if (dataLength < 2)
+				@throw [OFInvalidServerReplyException
+				    exception];
+
+			preference = (buffer[i] << 8) | buffer[i + 1];
+
+			j = i + 2;
+
 			data = parseName(buffer, length, &j,
 			    ALLOWED_POINTER_LEVELS);
 
 			if (j != i + dataLength)
 				@throw [OFInvalidServerReplyException
 				    exception];
 
-			break;
+			return [[[OFMXDNSResourceRecord alloc]
+			    initWithName: name
+			     recordClass: recordClass
+			      recordType: recordType
+			      preference: preference
+				    data: data
+				     TTL: TTL] autorelease];
 		case OF_DNS_RESOURCE_RECORD_TYPE_AAAA:
 			if (dataLength != 16)
 				@throw [OFInvalidServerReplyException
 				    exception];
 
-			class = [OFAAAADNSResourceRecord class];
-			data = parseAAAAData(&buffer[i]);
-			break;
-		default:
-			class = [OFDNSResourceRecord class];
-			data = [OFData dataWithItems: &buffer[i]
-					       count: dataLength];
-			break;
-		}
-	} else {
-		class = [OFDNSResourceRecord class];
-		data = [OFData dataWithItems: &buffer[i]
-				       count: dataLength];
-	}
-
-	return [[[class alloc] initWithName: name
-				recordClass: recordClass
-				 recordType: recordType
-				       data: data
-					TTL: TTL] autorelease];
+			data = parseAAAAData(&buffer[i]);
+
+			return [[[OFAAAADNSResourceRecord alloc]
+			    initWithName: name
+			     recordClass: recordClass
+			      recordType: recordType
+				    data: data
+				     TTL: TTL] autorelease];
+		default:
+			data = [OFData dataWithItems: &buffer[i]
+					       count: dataLength];
+
+			return [[[OFDNSResourceRecord alloc]
+			    initWithName: name
+			     recordClass: recordClass
+			      recordType: recordType
+				    data: data
+				     TTL: TTL] autorelease];
+		}
+	} else {
+		data = [OFData dataWithItems: &buffer[i]
+				       count: dataLength];
+
+		return [[[OFDNSResourceRecord alloc]
+		    initWithName: name
+		     recordClass: recordClass
+		      recordType: recordType
+			    data: data
+			     TTL: TTL] autorelease];
+	}
 }
 
 @implementation OFDNSResolver_context
 @synthesize host = _host, nameServers = _nameServers;
 @synthesize searchDomains = _searchDomains;

Index: src/OFDNSResourceRecord.h
==================================================================
--- src/OFDNSResourceRecord.h
+++ src/OFDNSResourceRecord.h
@@ -76,11 +76,11 @@
  * @brief The domain name to which the resource record belongs.
  */
 @property (readonly, nonatomic) OFString *name;
 
 /*!
- * @brief The class of the data.
+ * @brief The resource record class code.
  */
 @property (readonly, nonatomic) of_dns_resource_record_class_t recordClass;
 
 /*!
  * @brief The resource record type code.
@@ -96,10 +96,21 @@
  * @brief The number of seconds after which the resource record should be
  *	  discarded from the cache.
  */
 @property (readonly, nonatomic) uint32_t TTL;
 
+/*!
+ * @brief Initializes an already allocated OFDNSResourceRecord with the
+ *	  specified name, resource record class, resource record type, resource
+ *	  record data and resource record time to live.
+ *
+ * @param name The name of the resource record
+ * @param recordClass The class code for the resource record
+ * @param recordType The type code for the resource record
+ * @param data The data for the resource record
+ * @param TTL The time to live for the resource record
+ */
 - (instancetype)initWithName: (OFString *)name
 		 recordClass: (of_dns_resource_record_class_t)recordClass
 		  recordType: (of_dns_resource_record_type_t)recordType
 			data: (id)data
 			 TTL: (uint32_t)TTL OF_DESIGNATED_INITIALIZER;
@@ -141,10 +152,58 @@
  * A string with the alias.
  */
 @property (readonly, nonatomic) OFString *data;
 @end
 
+/*!
+ * @class OFMXDNSResourceRecord \
+ *	  OFDNSResourceRecord.h ObjFW/OFDNSResourceRecord.h
+ *
+ * @brief A class representing an MX DNS resource record.
+ */
+@interface OFMXDNSResourceRecord: OFDNSResourceRecord
+{
+	uint16_t _preference;
+}
+
+/*!
+ * The preference of the resource record.
+ */
+@property (readonly, nonatomic) uint16_t preference;
+
+/*!
+ * A string with the mail exchange.
+ */
+@property (readonly, nonatomic) OFString *data;
+
+- (instancetype)initWithName: (OFString *)name
+		 recordClass: (of_dns_resource_record_class_t)recordClass
+		  recordType: (of_dns_resource_record_type_t)recordType
+			data: (id)data
+			 TTL: (uint32_t)TTL OF_UNAVAILABLE;
+
+/*!
+ * @brief Initializes an already allocated OFMXDNSResourceRecord with the
+ *	  specified name, resource record class, resource record type, resource
+ *	  record preference, resource record data and resource record time to
+ *	  live.
+ *
+ * @param name The name of the resource record
+ * @param recordClass The class code for the resource record
+ * @param recordType The type code for the resource record
+ * @param preference The preference of the resource record
+ * @param data The data for the resource record
+ * @param TTL The time to live for the resource record
+ */
+- (instancetype)initWithName: (OFString *)name
+		 recordClass: (of_dns_resource_record_class_t)recordClass
+		  recordType: (of_dns_resource_record_type_t)recordType
+		  preference: (uint16_t)preference
+			data: (id)data
+			 TTL: (uint32_t)TTL OF_DESIGNATED_INITIALIZER;
+@end
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 extern OFString *_Nonnull of_dns_resource_record_class_to_string(
     of_dns_resource_record_class_t recordClass);

Index: src/OFDNSResourceRecord.m
==================================================================
--- src/OFDNSResourceRecord.m
+++ src/OFDNSResourceRecord.m
@@ -147,37 +147,111 @@
 }
 
 - (OFString *)description
 {
 	return [OFString stringWithFormat:
-	    @"<OFDNSResourceRecord:\n"
+	    @"<%@:\n"
 	    @"\tName = %@\n"
 	    @"\tClass = %@\n"
 	    @"\tType = %@\n"
 	    @"\tData = %@\n"
 	    @"\tTTL = %" PRIu32 "\n"
 	    @">",
-	    _name, of_dns_resource_record_class_to_string(_recordClass),
+	    [self className], _name,
+	    of_dns_resource_record_class_to_string(_recordClass),
 	    of_dns_resource_record_type_to_string(_recordType), _data, _TTL];
 }
 @end
 
 @implementation OFADNSResourceRecord
-- (OFString *)data
-{
-	return _data;
-}
+@dynamic data;
 @end
 
 @implementation OFAAAADNSResourceRecord
-- (OFString *)data
-{
-	return _data;
-}
+@dynamic data;
 @end
 
 @implementation OFCNAMEDNSResourceRecord
-- (OFString *)data
+@dynamic data;
+@end
+
+@implementation OFMXDNSResourceRecord
+@dynamic data;
+@synthesize preference = _preference;
+
+- (instancetype)initWithName: (OFString *)name
+		 recordClass: (of_dns_resource_record_class_t)recordClass
+		  recordType: (of_dns_resource_record_type_t)recordType
+			data: (id)data
+			 TTL: (uint32_t)TTL
+{
+	OF_INVALID_INIT_METHOD
+}
+
+- (instancetype)initWithName: (OFString *)name
+		 recordClass: (of_dns_resource_record_class_t)recordClass
+		  recordType: (of_dns_resource_record_type_t)recordType
+		  preference: (uint16_t)preference
+			data: (id)data
+			 TTL: (uint32_t)TTL
+{
+	self = [super initWithName: name
+		       recordClass: recordClass
+			recordType: recordType
+			      data: data
+			       TTL: TTL];
+
+	_preference = preference;
+
+	return self;
+}
+
+- (bool)isEqual: (id)otherObject
+{
+	OFMXDNSResourceRecord *otherRecord;
+
+	if (![otherObject isKindOfClass: [OFMXDNSResourceRecord class]])
+		return false;
+
+	otherRecord = otherObject;
+
+	if (![super isEqual: otherRecord])
+		return false;
+
+	if (otherRecord->_preference != _preference)
+		return false;
+
+	return true;
+}
+
+- (uint32_t)hash
+{
+	uint32_t hash;
+
+	OF_HASH_INIT(hash);
+
+	OF_HASH_ADD_HASH(hash, [super hash]);
+	OF_HASH_ADD(hash, _preference >> 8);
+	OF_HASH_ADD(hash, _preference);
+
+	OF_HASH_FINALIZE(hash);
+
+	return hash;
+}
+
+- (OFString *)description
 {
-	return _data;
+	return [OFString stringWithFormat:
+	    @"<%@:\n"
+	    @"\tName = %@\n"
+	    @"\tClass = %@\n"
+	    @"\tType = %@\n"
+	    @"\tPreference = %" PRIu16 "\n"
+	    @"\tData = %@\n"
+	    @"\tTTL = %" PRIu32 "\n"
+	    @">",
+	    [self className], _name,
+	    of_dns_resource_record_class_to_string(_recordClass),
+	    of_dns_resource_record_type_to_string(_recordType), _preference,
+	    _data, _TTL];
 }
 @end