Select the attachment, then press Enter to open the file with the associated default app. Picture and text attachments are opened automatically if View/Display Attachments Inline is enabled.

Select the attachment, then press Enter to open the file with the associated default app. Picture and text attachments are opened automatically if View/Display Attachments Inline is enabled.

No, I'm not referring to saving the file or viewing it in the program associated with the file type. I'm referring to the MacOS "Quick Look" feature where you simply press the spacebar to preview the file.

The method I described opens the file from a temporary directory, at least on Windows. The file is not saved unless done so manually.

There is no such thing as a 'preview' of a message or attachment. If any part of it has been viewed, it has been opened. It's not like a video that can be partially viewed while it's downloading.

The method I described opens the file from a temporary directory, at least on Windows. The file is not saved unless done so manually. There is no such thing as a 'preview' of a message or attachment. If any part of it has been viewed, it has been opened. It's not like a video that can be partially viewed while it's downloading.

Not true on MacOS: https://en.wikipedia.org/wiki/Quick_Look

All you have to do with common filetypes is select it, and press the spacebar. This works in Finder, but also throughout many apps - including the other email clients I use.

sfhowes said

The method I described opens the file from a temporary directory, at least on Windows. The file is not saved unless done so manually. There is no such thing as a 'preview' of a message or attachment. If any part of it has been viewed, it has been opened. It's not like a video that can be partially viewed while it's downloading.

Not true on MacOS: https://en.wikipedia.org/wiki/Quick_Look

Yes true on Apple operating system. It always strikes me just how hard it is to convince Apple users that some "feature" in their chosen operating system is just not supported. Until Thunderbird has special code to actually turn the MIME encoded part of the message body into an attachment for this APPLE feature to work, there is no file for it to work with.

POSTBOX implemented such special code in 2008 or there abouts. https://www.engadget.com/2009-03-05-postbox-beta-8-solves-issues-adds-quicklook-support.html There is no Thunderbird quick look support. There is a bug requesting it https://bugzilla.mozilla.org/show_bug.cgi?id=457546

Until Thunderbird has special code to actually turn the MIME encoded part of the message body into an attachment for this APPLE feature to work, there is no file for it to work with. POSTBOX implemented such special code in 2008 or there abouts. https://www.engadget.com/2009-03-05-postbox-beta-8-solves-issues-adds-quicklook-support.html There is no Thunderbird quick look support. There is a bug requesting it https://bugzilla.mozilla.org/show_bug.cgi?id=457546

THANK YOU, Matt! This is exactly the information I was looking for.

It seems like Thunderbird would already have the code for converting MIME types since you can already view images inline, and by virtue of the fact that it understands attachments and can save them to disk. In any case, the feature request outlines my question and want, and it appears to be a dormant request. A small hassle I'll work around.

Thanks again for the informative response.