Outlook renames attachment, but why

Hi Tim,

We appreciate that you reached out here at Microsoft Community Forum.

We understand that when receiving any emails with attachments on your Outlook, it replaced the last character of the file name to underscore. This issue depends on how the file is being uploaded or shared. Let me help you in the best way I can.

First off, let’s isolate the issue further. You mentioned that this result only happens to another email account in your Outlook application. Could you please verify if the email account in concern is a personal or a business email account? Also, which Office program they are using?

Are the users working in an organizational environment such as work or office?

Lastly, could you please elaborate on how the customer receives or opens the attachments on Outlook?

Please do update us with the results so we can assist you further with this issue. We’ll be looking forward to your next revert.

Hi. What is happening example: I create a new email to the client from my email client and attach a docx file attachment by dragging it - also used the add attachment option [no change]. Send the email to client, they receive it as  .doc_ when the email arrives and if they reply to me then i get it back the same way. If they try to open the attachment there is asks what program to associate to, but if they select the attachment and save as and rename the .doc_ to .docx then the attachment works fine. The same happens to all .pd_ .xls_ .jp_ and so on. The association of all extensions has been checked and all that is correct.

As mentioned they are on Office 2019 Home & Business and the latest build updates installed. It is a same home based business - the 2 email accounts are both business style email accounts, this one is on their domain name and the other is a different domain. They are on Win 10 as well and it is a brand new laptop - less than 1 month old and newly setup. Any emails going to the second domain are all received and sent fine, it is just mails to the primary email account that are being affected. 

Hi I am experiencing the same issue with both my email accounts on outlook. It started yesterday and its still happening today. Whats going on? I cant receive files that I can open. It wont even display images.

I don't have time to play computer doctor.

We appreciate you providing further information regarding this concern.  

We’ve seen that the issue is already isolated in a specific domain account. 

At this point, I'll be coordinating with our Internal Support Team to conduct further investigation and addressed the issue as soon as possible. 

Also, to assure that I will get accurate information on how to solve this matter. We'll let you know once we reach any updates. 

Please standby.

Kind regards. 

-Genevieve

Thank you for patiently waiting, Tim.

We got an update from our Internal Support Team, and they advise that you use an IMAP protocol to see if the issue will occur. This is because the POP configuration is a very old protocol and is missing a lot of features that IMAP had. That may help, especially if the other account that is working on your Outlook is using an IMAP configuration. 

Do update this post if you need further assistance. We are always here to help.

Hi,

I too am experiencing the same issue since few days back. I am using two email accounts in Outlook and I am using IMAP. This has really affected my day-to-day works as I cannot forward any e-mails attachments as it is. Also, I have to manually change file extensions of all incoming email atttachments.

Please help me to sort this matter out.

Regards,

Keerthi.

Hi,

I'm still having problem.

it is because Kaspersky Mail Anti virus. You must go to Mail antivirus settings. And disable "rename attachment files"