What kind of attachments are you trying to open, and with which application shall they be opened?

Word documents and adobe attachemnts

Then go to Tools menu > attachments and delete any references to doc, docx and pdf files.

Next time you select one to open you will be asked what application to use and you can save the action.

The only actions are Save Files to (Browse) or Always ask me where to save files. Do you have any other suggestions?

Where and when do you see these actions?

That sounds like an unknown file type. (unknown to your operating system, not Thunderbird) When you save the file to disk and double click it, does it open?

If yes, install this add-on and see if it helps. https://nic-nac-project.org/~kaosmos/index-en.html#openattach Instructions to install add-ons here http://chrisramsden.vfast.co.uk/3_How_to_install_Add-ons_in_Thunderbird.html

If no, what does happen?

They are pdf attachments, and I want to open them with Adobe Reader X1.

Nothing happens when I try to open the file, either right or left clicking on it. When I save it, there is a white page with the corner turned down. When I try to open it, a message says " File could not be opened because the associated helper application does not exist. Change the association in your preferences."

Have you installed the add-on?

The white square is an icon windows has used for decades to denote a file type it does not understand. It sounds to me like the person sending your mails is sending junk.

Perhaps they are an outlook user sending your winmail.dat files from an incorrectly configured copy of outlook. Perhaps the mail originates from one of the myriad defective web mail scripts that simply encode attachments incorrectly. (most web developers have no idea how to encode a mail, particularly those using outlook bevcause it does not do it correctly either.) I am trying to get enough information to understand.

Hi Matt, I did try to install the add-on, but it came up as a white square I could not open! They are genuine emails sent by my daughter mostly, as pdf., from Windows Live Mail, which I do not like, but although she uses Firefox, she has not been able to install T/bird, but that is another story. I am hoping that I have solved the problem, however. I had the same problems with things like bank statements, which I could neither open nor save. In the Firefox help department, I found out about options, attachments and scrolling down to make Adobe Reader the default browser, so in T/bird I went to tools, options, attachments and did the same thing there. It seems to work, so I just need to wait till someone sends me an email with a pdf attachment. If it works, great, and thanks for your help. If not, I will be back! Regards, Bill Ure