I have asked this quesiton on the Netherlands site, but nobody seems to know what the problem is. I asked the question previously there in 2019, and none of the responses yielded The Answer. I do know that my problem was solved after that, because I used both the "problem causing" Mail Merge document (and other MailMerge to attachment docs in 2019 with Office 2016, and then later in 2020 with Office 2019. I now have Office 2016 (64 bits) installed on a new computer, that has not had any versions of Office installed (not even a trial version).
Okay, here's the problem: I mail merge with an Access query. It looks fine on screen, and I can finish the Mailmerge to Email to text and html. But when I choose the "as attachement" option I get this error (translated from the Dutch): No email can be sent due to a MAPI malfunction. "An error occured when trying to open the attachment." The MS Word help is dumb: restart Outlook and Word in that order, and doesn't do anything.
When I use Word's File / Share / Email / As Attachement option to create an email with attachement, it preselects my hotmail account (I also have a Gmail account). This is how it has always worked; the emails generated with this MailMerge document have always gone out from my Hotmail address. Somebody mentioned something about Microsoft Exchange or something like that, but that is all he wrote, so I have no idea what to do with that tidbit. Download it, install it, turn it on, configure it, where, how, etc.
I have attempted the following:
Checked that Outlook is the standard Mail program. Control Panel indicates it is, besides I can share a Word document from File / Share / Email / As attachement and that opens an Outlook like New Email screen with the document attached. I can send that to myself and receive it moments later.
Start Word in Safe Mode.
Repair Office 2016 (I have not removed and reinstalled Office 2016 because I am wondering if I should install the 32 bits version instead of the 64 bits).
Turned off Norton 360 for 15 minutes.
Installed ClickYes and tried to MailMerge with it enabled and disabled.
None of the above (and possibly a few others) made any difference.
As mentioned (since I think it is significant): This document used to work fine under all versions of Office (including 2019) until I installed 2016 on a reformatted computer in 2019 and this same thing happened. I know I must have solved it, because I used MailMerge from Access to attachement with several different documents including this one that is now giving me fits.
The reason I wonder about the 32 bit version, is that I apparently downloaded the 64 and 32 bit version Installation Files for Office 2016 Pro from our Tech Soup account. With the computer I had at that time, I can't imagine why I would have downloaded the 32 bits version, unless I was told installing that version would solve this problem. I hate to go to the trouble to uninstall the 64 bits version, install the 32 bits version, find out it makes no difference and then uninstall it and re-install the 64 bits version. Besides, if the 32 bits version does work, I will never know for sure whether it was the re-install that solved the problem, or the 32 bits version.
I am stumped. And this letter should have gone out to the recipients last week (always a deadline, right?) Help me, please!