diff --git a/common/src/main/java/com/genexus/CommonUtil.java b/common/src/main/java/com/genexus/CommonUtil.java
index 42af5b2e8..f89416989 100644
--- a/common/src/main/java/com/genexus/CommonUtil.java
+++ b/common/src/main/java/com/genexus/CommonUtil.java
@@ -3490,4 +3490,69 @@ public static String Sanitize(String input, HashMap<Character, Character> whiteL
 		}
 		return sanitizedInput.toString();
 	}
+
+
+	public static boolean isKnownContentType(String type)
+	{
+		if (type != null)
+		{
+			for (int i = 0; i < contentTypes.length; i++)
+			{
+				if (contentTypes[i].length >= 2)
+				{
+					if (type.equalsIgnoreCase(contentTypes[i][1]))
+						return true;
+				}
+			}
+		}
+		return false;
+	}
+
+	public static String getContentFromExt( String extension)
+	{
+		if (extension != null)
+		{
+			extension = extension.toLowerCase();
+			for (int i = 0; i < contentTypes.length; i++) {
+				if (contentTypes[i][0].equals(extension.trim()))
+					return contentTypes[i][1];
+			}
+		}
+		return null;
+	}
+
+	private static final String contentTypes[][] = {
+		{"txt"     , "text/plain"},
+		{"rtx"     , "text/richtext"},
+		{"htm"     , "text/html"},
+		{"html" , "text/html"},
+		{"xml"     , "text/xml"},
+		{"aif"    , "audio/x-aiff"},
+		{"au"    , "audio/basic"},
+		{"wav"    , "audio/wav"},
+		{"bmp"    , "image/bmp"},
+		{"gif"    , "image/gif"},
+		{"jpe"    , "image/jpeg"},
+		{"jpeg"    , "image/jpeg"},
+		{"jpg"    , "image/jpeg"},
+		{"jfif"    , "image/pjpeg"},
+		{"tif"    , "image/tiff"},
+		{"tiff"    , "image/tiff"},
+		{"png"    , "image/x-png"},
+		{"3gp"    , "video/3gpp"},
+		{"3g2"    , "video/3gpp2"},
+		{"mpg"    , "video/mpeg"},
+		{"mpeg"    , "video/mpeg"},
+		{"mov"    , "video/quicktime"},
+		{"qt"    , "video/quicktime"},
+		{"avi"    , "video/x-msvideo"},
+		{"exe"    , "application/octet-stream"},
+		{"dll"    , "application/x-msdownload"},
+		{"ps"    , "application/postscript"},
+		{"pdf"    , "application/pdf"},
+		{"svg"    , "image/svg+xml"},
+		{"tgz"    , "application/x-compressed"},
+		{"zip"    , "application/x-zip-compressed"},
+		{"gz"    , "application/x-gzip"}
+	};
 }
diff --git a/gxmail/src/main/java/com/genexus/internet/SMTPSessionJavaMail.java b/gxmail/src/main/java/com/genexus/internet/SMTPSessionJavaMail.java
index 4e06763b8..1a0550be2 100644
--- a/gxmail/src/main/java/com/genexus/internet/SMTPSessionJavaMail.java
+++ b/gxmail/src/main/java/com/genexus/internet/SMTPSessionJavaMail.java
@@ -217,16 +217,31 @@ private void addAttachment(Multipart multipart, String fileNamePath, String atta
 		{
 			fileNamePath = attachDir + fileNamePath;
 		}
-		BodyPart messageBodyPart = new MimeBodyPart();
-		DataSource source = new FileDataSource(fileNamePath);
-		messageBodyPart.setDataHandler(new DataHandler(source));
+
 		if	(filename.lastIndexOf(File.separator) != -1)
 		{
 			filename = filename.substring(filename.lastIndexOf(File.separator) + 1);
 		}
+
+		int lastDot = filename.lastIndexOf('.');
+		String extension = (lastDot == -1) ? "" : filename.substring(lastDot + 1).toLowerCase();
+
+		String mt = CommonUtil.getContentFromExt(extension);
+		final String mimeType = (mt == null || mt.isEmpty()) ? "application/octet-stream" : mt;
+
+		DataSource source = new FileDataSource(fileNamePath) {
+			@Override
+			public String getContentType() {
+				return mimeType;
+			}
+		};
+
+		BodyPart messageBodyPart = new MimeBodyPart();
+		messageBodyPart.setDataHandler(new DataHandler(source));
 		messageBodyPart.setFileName(filename);
+
 		multipart.addBodyPart(messageBodyPart);
-   }	
+   }
 
 	public void logout(GXSMTPSession sessionInfo)
 	{
diff --git a/java/src/main/java/com/genexus/internet/HttpContext.java b/java/src/main/java/com/genexus/internet/HttpContext.java
index 2eae1a453..cf7ed307e 100644
--- a/java/src/main/java/com/genexus/internet/HttpContext.java
+++ b/java/src/main/java/com/genexus/internet/HttpContext.java
@@ -877,31 +877,12 @@ public boolean checkContentType(String contentKey, String contentType, String fu
 
 		public static boolean isKnownContentType(String type)
 		{
-			if (type != null)
-			{
-				for (int i = 0; i < contentTypes.length; i++)
-				{
-					if (contentTypes[i].length >= 2)
-					{
-						if (type.equalsIgnoreCase(contentTypes[i][1]))
-							return true;
-					}
-				}
-			}
-			return false;
+			return CommonUtil.isKnownContentType(type);
 		}
 
 		public static String getContentFromExt( String extension)
 		{
-		  if (extension != null)
-		  {
-			extension = extension.toLowerCase();
-			for (int i = 0; i < contentTypes.length; i++) {
-			  if (contentTypes[i][0].equals(extension.trim()))
-				return contentTypes[i][1];
-			}
-		  }
-		  return null;
+			return CommonUtil.getContentFromExt(extension);
 		}
 		
 		int GX_NULL_TIMEZONEOFFSET = 9999;
@@ -913,42 +894,6 @@ public void setRestService()
 
 	public boolean isRestService()
 	{ return restService; }		
-		
-		private static final String contentTypes[][] = {
-								{"txt" 	, "text/plain"},
-								{"rtx" 	, "text/richtext"},
-								{"htm" 	, "text/html"},
-								{"html" , "text/html"},
-								{"xml" 	, "application/xml"},
-								{"aif"	, "audio/x-aiff"},
-								{"au"	, "audio/basic"},
-								{"wav"	, "audio/wav"},
-								{"bmp"	, "image/bmp"},
-								{"gif"	, "image/gif"},
-								{"jpe"	, "image/jpeg"},
-								{"jpeg"	, "image/jpeg"},
-								{"jpg"	, "image/jpeg"},
-								{"jfif"	, "image/pjpeg"},
-								{"tif"	, "image/tiff"},
-								{"tiff"	, "image/tiff"},
-								{"png"	, "image/x-png"},
-								{"3gp"	, "video/3gpp"},
-								{"3g2"	, "video/3gpp2"},
-								{"mpg"	, "video/mpeg"},
-								{"mpeg"	, "video/mpeg"},
-								{"mov"	, "video/quicktime"},
-								{"qt"	, "video/quicktime"},
-								{"avi"	, "video/x-msvideo"},
-								{"exe"	, "application/octet-stream"},
-								{"dll"	, "application/x-msdownload"},
-								{"ps"	, "application/postscript"},
-								{"pdf"	, "application/pdf"},
-								{"svg"	, "image/svg+xml"},
-								{"tgz"	, "application/x-compressed"},
-								{"zip"	, "application/x-zip-compressed"},
-								{"gz"	, "application/x-gzip"},
-								{"json"	, "application/json"}
-								};
 
 		public boolean willRedirect()
 		{