Attachments from a Proximus-mailbox (Belgium) arrive in damaged condition in Thunderbird

[aquarius]

To Thunderbird team, and to all.
Since I few days I experience some problems opening attachments in Thunderbird.
It looks to be a translation problem between my genuine on-line mailbox at Belgian provider Proximus  and my Thunderbird application. The attachments, mostly JPG images, but sometimes .docx wordfiles cannot be opened by clicking in the Thunderbird application. When I save them on my hard-disk and try to open them there, I either get the message: "damaged file" (pictures) either I get a blanc sheet (docx).
Going back to my genuine on-line mailbox on the provider's website, the files are intact.
Thanks on beforehand for a clue;

[CB151]

I have the same problem.  And it is only with my email.  The jpg and pdf attached files I receive are corrupted.  My husband is on the same Thunderbird email and his attachments all open correctly.  Mine open OK in Outlook but not in Thunderbird.  Sure would love some help.

[Boobieta]

As a temporary fix, could you zip the files? Do zipped files arrive ok?