diff --git a/src/net/message.cpp b/src/net/message.cpp
index 1024bcba..09fe6321 100644
--- a/src/net/message.cpp
+++ b/src/net/message.cpp
@@ -29,6 +29,8 @@
 
 #include "vmime/net/message.hpp"
 
+#include <sstream>
+
 
 namespace vmime {
 namespace net {
@@ -52,6 +54,94 @@ size_t messagePart::getPartCount() const
 }
 
 
+
+// message::uid
+
+
+message::uid::uid()
+{
+}
+
+
+message::uid::uid(const string& uid)
+	: m_str(uid)
+{
+}
+
+
+message::uid::uid(const unsigned long uid)
+{
+	std::ostringstream oss;
+	oss.imbue(std::locale::classic());
+	oss << uid;
+
+	m_str = oss.str();
+}
+
+
+message::uid::uid(const char* uid)
+	: m_str(uid)
+{
+}
+
+
+message::uid::uid(const uid& other)
+{
+	m_str = other.m_str;
+}
+
+
+message::uid& message::uid::operator=(const uid& other)
+{
+	m_str = other.m_str;
+	return *this;
+}
+
+
+message::uid& message::uid::operator=(const string& uid)
+{
+	m_str = uid;
+	return *this;
+}
+
+
+message::uid& message::uid::operator=(const unsigned long uid)
+{
+	std::ostringstream oss;
+	oss.imbue(std::locale::classic());
+	oss << uid;
+
+	m_str = oss.str();
+
+	return *this;
+}
+
+
+message::uid::operator string() const
+{
+	return m_str;
+}
+
+
+bool message::uid::empty() const
+{
+	return m_str.empty();
+}
+
+
+bool message::uid::operator==(const uid& other) const
+{
+	return m_str == other.m_str;
+}
+
+
+std::ostream& operator<<(std::ostream& os, const message::uid& uid)
+{
+	os << static_cast <string>(uid);
+	return os;
+}
+
+
 } // net
 } // vmime
 
diff --git a/vmime/net/message.hpp b/vmime/net/message.hpp
index 76bfb16b..de5e884a 100644
--- a/vmime/net/message.hpp
+++ b/vmime/net/message.hpp
@@ -177,7 +177,30 @@ public:
 
 	/** The type for an unique message identifier.
 	  */
-	typedef string uid;
+	class uid
+	{
+	public:
+
+		uid();
+		uid(const string& uid);
+		uid(const unsigned long uid);
+		uid(const char* uid);
+		uid(const uid& other);
+
+		uid& operator=(const uid& other);
+		uid& operator=(const string& uid);
+		uid& operator=(const unsigned long uid);
+
+		operator string() const;
+
+		bool empty() const;
+
+		bool operator==(const uid& other) const;
+
+	private:
+
+		string m_str;
+	};
 
 	/** Return the MIME structure of the message (must fetch before).
 	  *
@@ -315,6 +338,9 @@ public:
 };
 
 
+VMIME_EXPORT std::ostream& operator<<(std::ostream& os, const message::uid& uid);
+
+
 } // net
 } // vmime