diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4d42f15c..74cf6814 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -655,6 +655,11 @@ IF(VMIME_HAVE_TLS_SUPPORT)
 	IF(VMIME_TLS_SUPPORT_LIB STREQUAL "gnutls")
 
 		INCLUDE(FindGnuTLS)
+
+		IF(NOT GNUTLS_FOUND)
+			MESSAGE(FATAL_ERROR "GnuTLS was selected for TLS support, but it was not found")
+		ENDIF()
+
 		SET(CMAKE_REQUIRED_LIBRARIES "${GNUTLS_LIBRARY}")
 		CHECK_FUNCTION_EXISTS(gnutls_priority_set_direct VMIME_HAVE_GNUTLS_PRIORITY_FUNCS)
 
@@ -685,6 +690,10 @@ IF(VMIME_HAVE_TLS_SUPPORT)
 
 		INCLUDE(FindOpenSSL)
 
+		IF(NOT OPENSSL_FOUND)
+			MESSAGE(FATAL_ERROR "OpenSSL was selected for TLS support, but it was not found")
+		ENDIF()
+
 		INCLUDE_DIRECTORIES(
 			${INCLUDE_DIRECTORIES}
 			${OPENSSL_INCLUDE_DIR}
@@ -709,6 +718,8 @@ IF(VMIME_HAVE_TLS_SUPPORT)
 
 	ENDIF()
 
+	MESSAGE(STATUS "TLS support library: ${VMIME_TLS_SUPPORT_LIB}")
+
 ENDIF(VMIME_HAVE_TLS_SUPPORT)
 
 
@@ -731,6 +742,10 @@ SET_PROPERTY(
 
 IF(VMIME_CHARSETCONV_LIB STREQUAL "iconv")
 
+	IF(NOT ICONV_FOUND)
+		MESSAGE(FATAL_ERROR "iconv was selected for charset conversion, but it was not found")
+	ENDIF()
+
 	INCLUDE_DIRECTORIES(
 		${INCLUDE_DIRECTORIES}
 		${ICONV_INCLUDE_DIR}
@@ -761,6 +776,10 @@ IF(VMIME_CHARSETCONV_LIB STREQUAL "iconv")
 
 ELSEIF(VMIME_CHARSETCONV_LIB STREQUAL "icu")
 
+	IF(NOT ICU_LIBRARIES)
+		MESSAGE(FATAL_ERROR "ICU was selected for charset conversion, but it was not found")
+	ENDIF()
+
 	INCLUDE_DIRECTORIES(
 		${INCLUDE_DIRECTORIES}
 		${ICU_INCLUDE_DIRS}
@@ -805,6 +824,8 @@ ELSE()
 
 ENDIF()
 
+MESSAGE(STATUS "Charset conversion library: ${VMIME_CHARSETCONV_LIB}")
+
 
 ##############################################################################
 # Platform