Exactly the problem I had.
Could it be an incorrect parsing of the .eml format by eM Client?
36 KB cannot became 0B
I BCC’d it to another address on a test machine running the current version of eM Client. This is how it appears.
I am wondering if it is not the server. Do you have another account setup in eM Client that is using a different server? If you do, send me that address to my email and I will send the test email to you again.
Gary - in an attempt to help triangulate, I will send you my email address as well, and if you will send me the same test email I’ll see how it looks on my end.
Gary/Bruno - The test email works perfectly on my end. Shows at 18k, hovering over it pops up a preview, and clicking on it opens it. What is the difference between my installation and Bruno’s? As noted, I’m on version 7.1.31849.0. This was extremely frustrating to me when it was occurring, so if there’s more I can do to help diagnose please let me know.
Unfortunately same version (on Windows 10) : (
An additional thought - Gary, the email address I gave you was of course a Gmail account. Per your earlier reply to Bruno, a non-Gmail account might have different results.
I think that the server is the difference. 
Well, perhaps, but recall that when I had the problem, the same email and attachment displayed correctly on my phone (different email client but identical accounts and servers).
Bruno, I assume this is an IMAP account. Can you right-click on the folder where the email is and choose Properties > Repair. Then open the email again and see if the attachment is viewable.
yes it’s an IMAP, with the Repair nothing change : (
You could remove the account from eM Client, then add it again. Other than that, don’t know what to say.
With Outlook for Web, I see correctly the email attachment on the same server where eM Client using IMAP doesn’t, quite strange!
Yes, it might be some incompatibility between eM Client and your server. Who hosts your email server?
But if I see it correctly on the web (Outlook for web), the server is not the same of the eM Client using IMAP?
Yes, but the way that eM Client interprets the information from that particular server may be different to the way another client or web app does it. RW sees my test email correctly on Gmail IMAP/POP3, and I see it correctly in my test using GMX IMAP. You see it incorrectly on the server you are using. We are all three using the same version of eM Client, so the only difference is the servers.
What is most likely is that your server is providing some unexpected information, or rather not providing some expected information. Your best option is to open a Pro Support ticket, and they will be able to assist you further, or at least pass this on to the developers.
Thank you for your time
No problem. Just let us know how you manage to resolve it.