Same problem here: when I select HTML in the Send As field of the Mail Recipient dialog it fails to send. It worked for me back in April and May with (slightly) earlier versions of Word and Outlook, but not now. In those cases I was using the same Excel
spreadsheet, but different Word documents.
Current software details:
Word 16.16 (180812)
Outlook 16.16 (180812)
MacOS 10.13.6
It works successfully if I select Text in the Send As field of the Mail Recipient dialog, but then my email looks terrible.
First error message: "Word was unable to mail your document."
Second error message: "Word could not finish merging these documents or inserting this database."
I tried changing fonts without success. I tried copying and then Paste Special as Unformatted text into a new Word doc and re-added all of my formatting without success. I tried copying and then Paste Special as Unformatted text into a new Word doc WITHOUT
recreating my formatting and THAT works! But again, then my email looks terrible (similar to Send As Text). So it appears that there is some formatting I am using in this document that the Mail Merge is unable to convert to HTML... BUT, taking the Unformatted
text version of the document that I added formatting to and then removing the formatting back out again (step by step, one type of formatting at a time) leaves me with a "plain text" version that STILL doesn't work.
I just tried two of the older successful Word docs, and they still work, so it must be some difference in formatting between this new doc and those older ones, but I can't figure out what it is. Interestingly, another older doc that DID work back in April
does NOT work now.
Okay, last test for today: I Command-A copied the contents of the original document and then pasted into a new Word doc as Unformatted text. Started mail merge, linked to Excel, inserted merge field, and sent as HTML - it worked! I then added an underline
to a single word and tried again: it worked! So then, thinking underlining is safe, I went through and added underlines to the rest of the doc where I want them - IT NO LONGER WORKS.
I'm stumped. Ideas?