What anti virus are you using? (yes I know it is an apple device.)

It is Avira and Sophos. By the way all other features (Excel, jpg, pdf also rtf) are working fine. Only doc or docx have problems. On my Android device the doc attachment mail shows two attachments, one the doc attachment which can be correctly opened and one small "unknown" attachment. These second attachment is not present with all the other attachments working fine.

Well disable the anti virus and see how you get on. The issue is Microsfts office document have a long and unhappy history of carrying malware embedded in them. So they get singled out for spacial attention by these wonders of the age, the anti virus products. Other file formats other than doc/docx that get special attention are excel and PDF.

Now in scanning these poorly tested products also have an amazing ability to corrupt the file before it is attached. They also do a good job of the same when mail is downloaded from the server. So as I said try disabling it in the forst instance. THe problem component could be mail scanning, but it is just as likely to be the "on access" scanning component.

I disabled anti virus, but the problem persists.

the correct word file has type=application/msword included.The two corupted files only filename

I have this problem too. Mac OSX 10.13 High Sierra. Thunderbird worked fine until 60.0. When I try to open Word attachments I have sent from my sent files, Word opens a "Convert File" box and gives me a selection of things that don't work. I may need to reinstall Thunderbird 59.2 and turn off updates until the software works.

ThFox said

I have this problem too. Mac OSX 10.13 High Sierra. Thunderbird worked fine until 60.0. When I try to open Word attachments I have sent from my sent files, Word opens a "Convert File" box and gives me a selection of things that don't work. I may need to reinstall Thunderbird 59.2 and turn off updates until the software works.

Interesting idea. What makes you think Thunderbird is your problem? What happens if you use mac mail on that account? Does it have issues with word docs?

The problem started simultaneously with the first update to 60. When I log into gmail directly in Firefox and send the word attachment the recipients report that there is no problem. Then there is this unresolved issue in Release Notes for 60.3 "Under some circumstances Thunderbird on Mac will send attachments using the so-called AppleDouble format which can lead to problems with mail servers and recipients" Case closed as far as I'm concerned. I have downdated back to 52.9 and will find out in the morning (it's night here) if that has taken care of it.

Bugzilla Bug 1506800 offers a "private update" to 60.3.2 that solves that problem

martgehl said

It is Avira and Sophos. <

Generally having more than one anti virus not only steels about 50% of your devices abilty to "compute" thet interact badly and usually one really messes up.

By the way all other features (Excel, jpg, pdf also rtf) are working fine. Only doc or docx have problems. On my Android device the doc attachment mail shows two attachments, one the doc attachment which can be correctly opened and one small "unknown" attachment. These second attachment is not present with all the other attachments working fine.

Then it is time to have a look at the message source. Each attachment should have it's own "block" in the message source. So what is going on that Thunderbird see's two attachments and your android devices see one.

I see the two attachments in my android device now, but I am not using an anti-virus on my Mac, since I get so many mixed messages on them.

I went to Bugzilla but didn't see how to download that 'private fix'. Perhaps it's beyond my knowledge/willingness. I have downgraded to 52.9 and (assuming it works as it used to tomorrow morning) I will hang here awhile waiting for Thunderbird to do a fix, as nearly every bit of work I do involves sending some kind of outdated word attachment compatible with the even more outdated systems of my recipients.

ThFox said

I went to Bugzilla but didn't see how to download that 'private fix'. Perhaps it's beyond my knowledge/willingness. I have downgraded to 52.9 and (assuming it works as it used to tomorrow morning) I will hang here awhile waiting for Thunderbird to do a fix, as nearly every bit of work I do involves sending some kind of outdated word attachment compatible with the even more outdated systems of my recipients.

A link to the fixed TB 60.3.2 is here. Direct dmg link.