PDF attachments from outlook open in reader instead of full acrobat

[davidm19816265]

Hello all, 

I think the subject describes the issue. I have set Acrobat as the default app, and I have tried managing the Outlook add-in, but PDF attachments still open in Reader rather than full Acrobat when I open a PDF from an attachment. If I save the attachment elsewhere, then it will open in the full version. Any ideas on how I can open a PDF directly to the full version when opening from an attachment in Outlook? 

[Tariq Ahmad]

Hi @davidm19816265,

That does sound frustrating — thank you for detailing what you’ve already tried. What you’re running into is a known behavior with Outlook: when you open a PDF directly from an attachment, it first saves a temporary copy into Outlook’s cache folder. Windows then uses whichever PDF handler is associated with certain registry entries for “Outlook temp files,” which can differ from your system-wide default. That’s why saving the file elsewhere works correctly, but opening directly from Outlook defaults to Reader.

A few things you can try:

1. Check Windows Default Apps

   • Confirm under Settings > Apps > Default apps that Adobe Acrobat (not Reader) is set as the default for .pdf.

   • Sometimes, uninstalling Reader (if not needed) resolves this completely, since Windows and Outlook will only see Acrobat as the handler.

2. Repair Office + Acrobat

   • Run a Quick Repair on Outlook/Office.

   • In Acrobat, go to Help > Repair Installation.

3. Outlook Trust Center Settings

   • Outlook has its own attachment handling logic. Go to File > Options > Trust Center > Trust Center Settings > Attachment Handling. Check whether any PDF previewer or Reader reference is active there. If so, disable/unregister it.

4. Registry-level fix (advanced)

   • In some cases, the “PreviewHandler” or AcroExch.Document.DC vs. AcroExch.Document.Reader association needs adjusting in the registry. This is more advanced, so if the issue persists, Adobe/IT admins may need to align those keys so that attachments also honor the Acrobat app.

As a quick test, if you temporarily uninstall Reader, Outlook should begin opening attachments in Acrobat, confirming that this is indeed a handler conflict.

Let us know how this goes.

Best regards,
Tariq | Adobe Community Team

[davidm19816265]

I've addressed everything except the registry. One strage thing, I can't even find the Acrobat Reader program/app on my computer. It isn't listed with the apps and it doesn't appear in the program list through control panel. It doesn't appear to be part of my Adobe cloud account. The only time I can see it is if I go to task manager when it is open, and then it will appear as a subprogram under HP Sure Click. 

[Dave Creamer of IDEAS]

What happens if you disable Sure Click?

Are you in a corporate environment?

What happens if you disable the Attachment Preview in Outlook?

[davidm19816265 · Accepted solution]

It looks like Sure Click opens the PDF in a quarantined version of Acrobat Reader to guard against malware and phishing links, etc. I'm not going to mess with it. Now that I know what is going on I can bite the bullet and save the PDF files I need locally and then open them in the full version. Thank you for the input.