The mail-merge add-on is very useful, and in general much better than the Microsoft Word - > Outlook workflow.
However, the main thing I think is missing (or, I’ve not worked out how to do it yet) is to filter based on the value of a column in the linked spreadsheet (e.g. you only want to send an email to everyone who has responded to a previous email, which you track via a “response” column with values “y” or “n”). Is this possible somehow (without filtering the spreadsheet and creating a copy of it)?
I’m also not sure I understand the difference between “send later” and “save to drafts” - does it matter which one to use?