I'm using Windows 10 OS

• The 'Settings' > 'Default apps' says 'photo viewer' uses 'Photos'
• The 'Default application by file type' says jpg and jpeg uses 'Photos'

Q: What have you got set up for default apps ?

In Thunderbird - tested using 128.9.1esr and beta 138.0b2

• Settings > General
• 'Files & Attachments'
• Content Type: JPEG image Action Use Photos (default)
• I also have 'Always ask me where to save files'

Please try selecting the default set for computer.

Test: When I 'double click' on a jpg or jpeg attachment it auto opens using 'Photos' When I 'right click' and select 'open' on a jpg or jpeg attachment it auto opens using 'Photos'

Q: What OS are you using? Q: What version of Thunderbird are you using?

Q: Where did you get the download for Thunderbird ? Q: Was it from the official website: https://www.thunderbird.net/en-US/thunderbird/all/ OR Windows App store Or Snap or Flatpak etc

Q: Do you have the Thunderbird profile in the default location or elsewhere?

Thank you for your help. Unfortunately not solved. I am windows 11 24H2. I have checked in windows settings and photos is the apps option. Thunderbird settings There is no option for photos under files and attachments nor anyone marked as default. The jpg content is showing a logo for Adobe photoshop elements and even when that is not chosen as a method to open the logo is still there by the jpg. I have always ask as where to save. See image

Just to be clear - you will never see a 'Content Type' for Photos. Choosing 'Photos' is setting an Action for a Content Type. You have to set the 'Action' for the 'JPG file'. The Content Type: 'JPG file' currently has the Action 'Use Firefox' - so you have instructed files with a jpg extention to open in the Firefox browser. For the Action - Click on the 'Use Firefox' drop down to see what is available, It should have 'Photos' in the drop down list because you say it is the default on computer - please select 'Use Photos (default)' - see image.

Again thank you. The example image shows Firefox as an example that the logo by jpg is still showing Adobe photoshop even though firefox is chosen. It does not open in Firefox or anything else. There is no Photos in the drop down list.

re : . I have checked in windows settings and photos is the apps option.

The default app to show images is 'Photos' - that's good.

The reason you have an Adobe Elements logo in the Thunderbird 'Content Type' is because you have set up file type jpg to use adobe photoshop elements. That needs to be fixed.

I still need you to check the computer 'Default application by file type' for jpg and jpeg because you have it set up for Adobe photoshop elements and it should be Photos.

See image below as an aid - you may see this better in this forum where you can clickon the thumbnail image and it should appear much larger.

In bottom windows search type : file type select 'Choose a default app for each type of file' Scroll down to see .jpg and also .jpeg Click on the icon which I bet is the adobe elements icon. A new small window opens - select 'Photos' Set both jpg and jpeg to use Photos.

You may discover you have to set up this file type first and then try to set up the Content Type Action in Thunderbird.

Magic thank you. I have changed the default application by file type to photo you are so right it was adobe elements. However it has not carried over into thunderbird settings, though the logo is now photo not adbove, there is still no option of photos in the drop down list of files and attachments. I have set it to always ask. I have shut down and restarted in the hope it would sort itself but still no joy. Sorry to be a pain.

By any chance do you use OWL for exchange addon ? If yes please read: https://addons.thunderbird.net/en-US/thunderbird/addon/owl-for-exchange/reviews/1175986/

In 'Settings' > 'General' Files & Attachments For JPG Content Type Click on the Action drop down and select 'use other' Does the 'Photo' option now appear ?

My only add on is import/export NG. Sorry I have no idea what OWL is. jpg - use other has no photo option - see image jpeg - does now have this option and I have set it to photo default. Doesn't open from thunderbird by double click.

Image - I presume there is no 'Photos' above 'Firefox' ? There is a scroll bar so just wondering if it's above Firefox.

The buttons are not showing properly, but this is a bug which I've reported. However, as a heads up - the slither of top edge of a grey button shown bottom far left is the 'Browse' button, the slither of blue is 'OK' and the slither on far right is 'Cancel'.

As the attachment you are trying to open is a jpg, you could try : In Files & Attachments - Click on the 'Action' and select 'Delete Action'.

In email Single click on attachment and it should offer 'what should Thunderbird do with this file' Select 'Open with' and choose 'Photos default' which should be in list Select 'Do this automatically for files like this from now on' Click on 'OK'

The two items above on the slider are mspaint and snipping tool. The bug in the display info is really helpful as I have had to close the item each time to get out! now I can cancel. I have deleted the jpg action. Unfortunately still nothing on thunderbird, I can get a menu that says open on right click, but nothing happens when used. This has been the case all along. For info before I deleted the jpg the Application details screen showed as below, no option for photos, just firefox and adobe photo. Thank you so much for your time on this problem it is really kind.

Can you recheck the following:

In bottom windows search type : file type select 'Choose a default app for each type of file' Scroll down to see .jpe, .jpg and also .jpeg All three of these need to have 'Photos' set up as their default appications.

Are all three set up to use 'Photos' ? Please post an image of what you see.

Test - is 'Photos' auto opening or can be selected generally for image files stored on computer. Not in Thunderbird - but test on any image file you have saved on computer that has the .JPG and also Test a .JPEG

I need you to double click on the image file and see if Photos auto opens and displays the image. OR right click on file and select 'Open with' and see if Photos is in the list and if yes, select it to see if it works.

Basically, testing to see if Photos is working ok on the computer.

Once you have checked that the application by file type says .jpg is set to use 'Photos'.... I need to know if you have done this: Settings > General Files & Attachments'

Content Type: .jpg Did you completely remove this by clicking on the 'Action to see drop down and selected 'Remove Action' ? So there is no .jpg content type - it has completely gone from list.

Can you then do this: In email Double click on .jpg attachment and it should open a small window saying 'You have chosen to open' ....and asking 'What should Thunderbird do with this file' Select 'Open with' Click on the drop down to show list. Post an image showing what it offers in the list.

OK I will try and work through your suggestions. 1. bottom window file type see screens joined. 2. Yes Photos opens a jpg from file explorer 3 Think I may have got lost here. I have removed jpg from the Thunderbird settings General files and attachments, nothing there now. image thunderbird. click on open nothing happens.

I hope this is helpful

Your attachment says it is a .jpeg - I thought the issue was a .jpg - no worries. At least we know .jpg is set up correctly in that area.

This time - check that the application by file type for .jpeg and it's set to use 'Photos' by default.

Then check this in Thunderbird Settings > General 'Files & Attachments' Content Type: .jpeg Is there a specific entry for JPEG ? If yes, is it set up to 'use Photos default' ?

Please Exit Thunderbird so we can be sure all the Attachment data has got updated, then Start Thunderbird again.

thunderbird does not open jpeg or jpg. For either the menu shows on right click, as image, but nothing happens when Open is clicked. Both work in photos from file explorer. Thunderbird settings have an option for jpeg which is set to photos default. There is no longer a jpg option as I removed it. Have shut down and restarted no change.

I think what we might be looking at here is incorrectly encoded files. With internet and hence mail file extensions are entirely meaningless to the correct identification of file types. This has significant security implications over the Windows use of file extensions.

To check the correct encoding will require you to have a look at the actual message source.

Each attachment is encoded as plain text when it is attached and the block of text that represents the attachment is preceded by a description in the messages source which includes the media type. So click on your email and press Ctrl+U to open a windows with the message source.

Scroll down through the source looking for a block of text that looks like the following example of a PDF file

Content-Type: application/pdf; name="Pay.pdf" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="Pay.pdf"

In identifying the media type the Content type is critical. In this example is is given as application/pdf in the case of a JPG file it should be given as image/jpeg See https://developer.mozilla.org/en-US/docs/Web/Media/Guides/Formats/Image_types#jpeg_joint_photographic_experts_group_image

What I have been seeing in recent years is an increasing number of poorly informed Microsoft tools using developers that encode everything as applications/octet stream that demonstrate their ignorance by relying on the file extension to identify the content.

If we can identify you are receiving poorly/incorrectly formatted emails, there is an addon that will open the attachments by extension as windows does https://addons.thunderbird.net/en-US/thunderbird/addon/openattachmentbyextension/?src=search You will not have the benefit of the increased security that using media types provides, but oyu will be able to communicate freely with the ignorant.

Content-Type: image/jpeg; name="Viper.jpg" Content-Disposition: attachment; filename="Viper.jpg" Content-Transfer-Encoding: base64 Content-ID: <f_m9sew9gr0> X-Attachment-Id: f_m9sew9gr0

this is what I have found on an email.

and what exactly happens when you double click the attachment?

Nothing!