diff --git a/src/chat/modifier/cpim-chat-message-modifier.cpp b/src/chat/modifier/cpim-chat-message-modifier.cpp
index 04c73f9c1..39104a674 100644
--- a/src/chat/modifier/cpim-chat-message-modifier.cpp
+++ b/src/chat/modifier/cpim-chat-message-modifier.cpp
@@ -38,29 +38,30 @@ LINPHONE_BEGIN_NAMESPACE
 ChatMessageModifier::Result CpimChatMessageModifier::encode (const shared_ptr<ChatMessage> &message, int &errorCode) {
 	Cpim::Message cpimMessage;
 
-	Cpim::FromHeader cpimFromHeader(cpimAddressUri(message->getFromAddress()), cpimAddressDisplayName(message->getFromAddress()));
-	cpimMessage.addMessageHeader(cpimFromHeader);
-	Cpim::ToHeader cpimToHeader(cpimAddressUri(message->getToAddress()), cpimAddressDisplayName(message->getToAddress()));
-	cpimMessage.addMessageHeader(cpimToHeader);
+	cpimMessage.addMessageHeader(
+		Cpim::FromHeader(cpimAddressUri(message->getFromAddress()), cpimAddressDisplayName(message->getFromAddress()))
+	);
+	cpimMessage.addMessageHeader(
+		Cpim::ToHeader(cpimAddressUri(message->getToAddress()), cpimAddressDisplayName(message->getToAddress()))
+	);
+	cpimMessage.addMessageHeader(
+		Cpim::DateTimeHeader(message->getTime())
+	);
 
 	if (message->getPrivate()->getPositiveDeliveryNotificationRequired()
 		|| message->getPrivate()->getNegativeDeliveryNotificationRequired()
 		|| message->getPrivate()->getDisplayNotificationRequired()
 	) {
 		const string imdnNamespace = "imdn";
-		Cpim::NsHeader cpimNsHeader(imdnNamespace, "<urn:ietf:params:imdn>");
-		cpimMessage.addMessageHeader(cpimNsHeader);
+		cpimMessage.addMessageHeader(Cpim::NsHeader("urn:ietf:params:imdn", imdnNamespace));
 
 		char token[13];
 		belle_sip_random_token(token, sizeof(token));
-		Cpim::GenericHeader cpimMessageIdHeader;
-		cpimMessageIdHeader.setName("Message-ID"); // TODO: Replace by imdnNamespace + ".Message-ID");
-		cpimMessageIdHeader.setValue(token);
-		cpimMessage.addMessageHeader(cpimMessageIdHeader);
+		cpimMessage.addMessageHeader(
+			Cpim::GenericHeader("Message-ID", token) // TODO: Replace by imdnNamespace + ".Message-ID");
+		);
 		message->getPrivate()->setImdnMessageId(token);
 
-		Cpim::GenericHeader dispositionNotificationHeader;
-		dispositionNotificationHeader.setName(imdnNamespace + ".Disposition-Notification");
 		vector<string> dispositionNotificationValues;
 		if (message->getPrivate()->getPositiveDeliveryNotificationRequired())
 			dispositionNotificationValues.emplace_back("positive-delivery");
@@ -68,8 +69,12 @@ ChatMessageModifier::Result CpimChatMessageModifier::encode (const shared_ptr<Ch
 			dispositionNotificationValues.emplace_back("negative-delivery");
 		if (message->getPrivate()->getDisplayNotificationRequired())
 			dispositionNotificationValues.emplace_back("display");
-		dispositionNotificationHeader.setValue(Utils::join(dispositionNotificationValues, ", "));
-		cpimMessage.addMessageHeader(dispositionNotificationHeader);
+		cpimMessage.addMessageHeader(
+			Cpim::GenericHeader(
+				imdnNamespace + ".Disposition-Notification",
+				Utils::join(dispositionNotificationValues, ", ")
+			)
+		);
 	}
 
 	const Content *content;
@@ -85,13 +90,16 @@ ChatMessageModifier::Result CpimChatMessageModifier::encode (const shared_ptr<Ch
 
 	const string contentBody = content->getBodyAsString();
 	if (content->getContentDisposition().isValid()) {
-		Cpim::GenericHeader contentDispositionHeader("Content-Disposition", content->getContentDisposition().asString());
-		cpimMessage.addContentHeader(contentDispositionHeader);
+		cpimMessage.addContentHeader(
+			Cpim::GenericHeader("Content-Disposition", content->getContentDisposition().asString())
+		);
 	}
-	Cpim::GenericHeader contentTypeHeader("Content-Type", content->getContentType().asString());
-	cpimMessage.addContentHeader(contentTypeHeader);
-	Cpim::GenericHeader contentLengthHeader("Content-Length", to_string(contentBody.size()));
-	cpimMessage.addContentHeader(contentLengthHeader);
+	cpimMessage.addContentHeader(
+		Cpim::GenericHeader("Content-Type", content->getContentType().asString())
+	);
+	cpimMessage.addContentHeader(
+		Cpim::GenericHeader("Content-Length", to_string(contentBody.size()))
+	);
 	cpimMessage.setContent(contentBody);
 
 	Content newContent;
@@ -116,76 +124,70 @@ ChatMessageModifier::Result CpimChatMessageModifier::decode (const shared_ptr<Ch
 
 	const string contentBody = content->getBodyAsString();
 	const shared_ptr<const Cpim::Message> cpimMessage = Cpim::Message::createFromString(contentBody);
-	if (!cpimMessage) {
+	if (!cpimMessage || !cpimMessage->getMessageHeader("From") || !cpimMessage->getMessageHeader("To")) {
 		lError() << "[CPIM] Message is invalid: " << contentBody;
 		errorCode = 500;
 		return ChatMessageModifier::Result::Error;
 	}
 
 	Content newContent;
-	bool contentTypeFound = false;
-	Cpim::Message::HeaderList l = cpimMessage->getContentHeaders();
-	if (l) {
-		for (const auto &header : *l.get()) {
-			if (header->getName() == "Content-Disposition") {
-				newContent.setContentDisposition(ContentDisposition(header->getValue()));
-			} else if (header->getName() == "Content-Type") {
-				contentTypeFound = true;
-				newContent.setContentType(ContentType(header->getValue()));
-			}
-		}
-	}
-	if (!contentTypeFound) {
+	auto contentTypeHeader = cpimMessage->getContentHeader("Content-Type");
+	if (!contentTypeHeader) {
 		lError() << "[CPIM] No Content-type for the content of the message";
 		errorCode = 500;
 		return ChatMessageModifier::Result::Error;
 	}
+	newContent.setContentType(ContentType(contentTypeHeader->getValue()));
+	auto contentDispositionHeader = cpimMessage->getContentHeader("Content-Disposition");
+	if (contentDispositionHeader)
+		newContent.setContentDisposition(ContentDisposition(contentDispositionHeader->getValue()));
 	newContent.setBody(cpimMessage->getContent());
 
 	message->getPrivate()->setPositiveDeliveryNotificationRequired(false);
 	message->getPrivate()->setNegativeDeliveryNotificationRequired(false);
 	message->getPrivate()->setDisplayNotificationRequired(false);
 
-	Address cpimFromAddress;
-	Address cpimToAddress;
-	l = cpimMessage->getMessageHeaders();
-	if (l) {
-		string imdnNamespace = "";
-		for (const auto &header : *l.get()) {
-			if (header->getName() == "NS") {
-				string val = header->getValue();
-				size_t startPos = 0;
-				startPos = val.find("<", startPos);
-				if (startPos == string::npos)
-					break;
-				size_t endPos = 0;
-				endPos = val.find(">", startPos);
-				if (endPos == string::npos)
-					break;
-				if (val.substr(startPos, endPos) == "<urn:ietf:params:imdn>")
-					imdnNamespace = Utils::trim(val.substr(0, startPos));
-			}
-		}
-		for (const auto &header : *l.get()) {
-			if (header->getName() == "From")
-				cpimFromAddress = Address(header->getValue());
-			else if (header->getName() == "To")
-				cpimToAddress = Address(header->getValue());
-			else if ((header->getName() == "Message-ID") || (header->getName() == (imdnNamespace + ".Message-ID")))
-				message->getPrivate()->setImdnMessageId(header->getValue());
-			else if ((header->getName() == (imdnNamespace + ".Disposition-Notification"))) {
-				vector<string> values = Utils::split(header->getValue(), ", ");
-				for (const auto &value : values)
-					if (value == "positive-delivery")
-						message->getPrivate()->setPositiveDeliveryNotificationRequired(true);
-					else if (value == "negative-delivery")
-						message->getPrivate()->setNegativeDeliveryNotificationRequired(true);
-					else if (value == "display")
-						message->getPrivate()->setDisplayNotificationRequired(true);
+	string imdnNamespace = "";
+	auto messageHeaders = cpimMessage->getMessageHeaders();
+	if (messageHeaders) {
+		for (const auto &header : *messageHeaders.get()) {
+			if (header->getName() != "NS")
+				continue;
+			auto nsHeader = static_pointer_cast<const Cpim::NsHeader>(header);
+			if (nsHeader->getUri() == "urn:ietf:params:imdn") {
+				imdnNamespace = nsHeader->getPrefixName();
+				break;
 			}
 		}
 	}
 
+	auto fromHeader = static_pointer_cast<const Cpim::FromHeader>(cpimMessage->getMessageHeader("From"));
+	Address cpimFromAddress(fromHeader->getValue());
+	auto toHeader = static_pointer_cast<const Cpim::ToHeader>(cpimMessage->getMessageHeader("To"));
+	Address cpimToAddress(toHeader->getValue());
+	auto dateTimeHeader = static_pointer_cast<const Cpim::DateTimeHeader>(cpimMessage->getMessageHeader("DateTime"));
+	if (dateTimeHeader)
+		message->getPrivate()->setTime(dateTimeHeader->getTime());
+
+	auto messageIdHeader = cpimMessage->getMessageHeader("Message-ID"); // TODO: For compatibility, to remove
+	if (!imdnNamespace.empty()) {
+		if (!messageIdHeader)
+			messageIdHeader = cpimMessage->getMessageHeader("Message-ID", imdnNamespace);
+		auto dispositionNotificationHeader = cpimMessage->getMessageHeader("Disposition-Notification", imdnNamespace);
+		if (dispositionNotificationHeader) {
+			vector<string> values = Utils::split(dispositionNotificationHeader->getValue(), ", ");
+			for (const auto &value : values)
+				if (value == "positive-delivery")
+					message->getPrivate()->setPositiveDeliveryNotificationRequired(true);
+				else if (value == "negative-delivery")
+					message->getPrivate()->setNegativeDeliveryNotificationRequired(true);
+				else if (value == "display")
+					message->getPrivate()->setDisplayNotificationRequired(true);
+		}
+	}
+	if (messageIdHeader)
+		message->getPrivate()->setImdnMessageId(messageIdHeader->getValue());
+
 	// Modify the initial message since there was no error
 	message->setInternalContent(newContent);
 	if (cpimFromAddress.isValid())