Mail Merge attachments are missing Content-ID
When I use “Mail Merge with Attachments” to send PDFs, it looks like it works correctly, and I see the attachments when I look at my Sent Mail in Gmail.
However, recipients who use Apple Mail report that they can’t see the attachments. I’m trying to troubleshoot that.
If I look at the raw message text (“Show original” in Gmail) for the email generated by Mail Merge, I see that the “Content-ID” for each attachment is blank. When I manually send an email with attachments, each attachment has a unique “Content-ID” value. I don’t know if that’s causing the error, but it’s the only difference I can see.