CMP MimeCheck

CMP MimeCheck

To view this page, you should have the most recent Java installed 32-bit JRE (Java Runtime Environment) 1.8.0_20.
This Applet will run online in your browser, but it is a hybrid you can also download, install and run it on your own machine as standalone application. It will start and run faster if you do that. It will also work safely even if you have disabled Java in your browser.

This Applet will tell you what your server is sending for MIME (Multipurpose Internet Mail Extensions) types and what it should be. If you discover errors in the what it server is sending, notify the ISP (Internet Service Provider). If you discover errors in what the MIME type should be, notify me.

more information on MIME types
other downloads
Alternatively you can download Mimecheck and run it as an application. Applet failed to run. No Java 1.7 or later plug-in found.

Java Requirements and Troubleshooting

MimeCheck is a signed Java Applet (that can also be run as an application) to MIME Check. You are welcome to install it on your own website. If it does not work…
  1. Often problems can be fixed simply by clicking the reload button on your browser.
  2. Make sure you have both JavaScript and Java enabled in your browser.
  3. Make sure the Java in your browser is enabled in the security tab of the Java Control panel. Click Start ⇒ Control Panel ⇒ Programs ⇒ Java ⇒ Security ⇒ Enable Java Content in the browser.
  4. If the security system is blocking you from running the program, at the bottom of that same security tab, add to the Exception Site List.
  5. This signed Java Applet (that can also be run as an application) needs 32-bit or 64-bit Java 1.7 or later. For best results use the latest 1.8.0_20. In the Java Control Panel, configure medium security to allow vanilla unsigned applets to run. If medium is not available use high security and add to the Exception Site List.
  6. You also need a recent browser.
  7. It works under any operating system that supports Java e.g. W2K/XP/W2003/Vista/W2008/W7-32/W7-64/W8-32/W8-64/W2012/Linux/LinuxARM/LinuxX86/LinuxX64/Ubuntu/Solaris/SolarisSPARC/SolarisSPARC64/SolarisX86/SolarisX64/OSX
  8. You should see the Applet hybrid above looking much like this screenshot. If you don’t, the following hints should help you get it working:
  9. For this Applet hybrid to work, you must click grant/accept to give it permission to read from any server on the web. If you refuse to grant permission, the program may crash with an inscrutable stack dump on the console complaining about AccessController.checkPermission.
  10. Optionally, you may permanently install the Canadian Mind Products code-signing certificate so you don’t have to grant each time.
  11. If the above Applet hybrid appears to freeze-up, click Alt-Esc repeatedly to check for any buried permission dialog box.
  12. If you have certificate troubles, check the installed certificates and remove or update any obsolete or suspected defective certificates. The only certificate used by this program is mindprodcert2014dsa.cer.
  13. Especially if this Applet hybrid has worked before, try clearing the browser cache and rebooting.
  14. To ensure your Java is up to date, check with Wassup. First, download it and run it as an application independent of your browser, then run it online as an Applet to add the complication of your browser.
  15. If the above Applet hybrid does not work, check the Java console for error messages.
  16. If the above Applet hybrid does not work, you might have better luck with the downloadable version available below.
  17. If you are using Mac OS X and would like an improved Look and Feel, download the QuaQua look & feel from UnZip the contained quaqua.jar and install it in ~/Library/Java/Extensions or one of the other ext dirs.
  18. If you are using Microsoft Internet Explorer 7, 8 or 9, try another browser. Seriously. Microsoft has taken great pains, over and over, to screw up Java and every other multi-platform standardisation.
  19. If you are using Microsoft Internet Explorer 7, 8 or 9, you must click to allow blocked content permission for Active X to run. This also gives permission to Java to run. Click the Information bar, and then click Allow blocked content. Unfortunately, this also allows dangerous ActiveX code to run. However, you must do this in order to get access to perfectly-safe Java Applets running in a sandbox. This is part of Microsoft’s war on Java. Don’t put up with it! Use a different browser.
  20. If you are using Microsoft Internet Explorer 9, makes sure the Java Plug-In SSV helper add-in is installed and enabled. If it is not, try reinstalling the Java JRE.
  21. If you have Windows 7 64-bit and Internet Explorer 64-bit, in theory you can use 64-bit Java, but I never been able to get it to work.
  22. Try upgrading to a more recent version of your browser, or try a different browser e.g. Firefox, SeaMonkey, Safari or Avant.
  23. If you still can’t get the program working click HELP for more detail.
  24. If you can’t get the above Applet hybrid working after trying the advice above and from the HELP button below, have bugs to report or ideas to improve the program or its documentation, please send me an email atemail Roedy Green.
Java powered   Get New Java  Get New Browser   Help
4.5 2011-10-31 free Java
more infoprecisscreenshotbrowse source repository
for the current version of MimeCheck.
Ensures server is sending the correct MIME types.
download 597K zip for MimeCheck Java source, compiled class files, jar and documentation to run on your own machine either as an application or an Applet.

Runs on any OS that supports Java e.g. W2K/XP/W2003/Vista/W2008/W7-32/W7-64/W8-32/W8-64/W2012/Linux/LinuxARM/LinuxX86/LinuxX64/Ubuntu/Solaris/SolarisSPARC/SolarisSPARC64/SolarisX86/SolarisX64/OSX.

First install the most recent Java.

To install, extract the zip download with WinZip, (or similar unzip utility) into any directory you please, often J:\ — ticking off the use folder names option.

To check out the corresponding source from the Subversion repository, use the TortoiseSVN repo-browser to
access mimecheck source in repository with [Tortoise] Subversion client on

After you have installed the jar, you can run it as an application. Type:

java -jar J:\com\mindprod\mimecheck\mimecheck.jar

adjusting as necessary to account for where the jar file is.

download ASP PAD XML program description for the current version of MimeCheck.

$1989.00 US donated so far. If the CMP utilities solved your problem, please donate a buck or two, or donate to one of the charities featured in the footer public service ads throughout the website and get a tax receipt.

MimeCheck is free. Full source included. You may even include the source code, modified or unmodified in free/commercial open source/proprietary programs that you write and distribute. Non-military use only.
MIME types
other downloads
Repairing Browser JNLP/JWS MIME Association
Repairing Windows JNLP/JWS Association

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