HOW TO CREATE MERGE DRAFT
Add-on creates for each row in a sheet a copy of the draft you selected and fills in data from the source sheet. Add-on searches for special combinations of characters in the draft so-called merge fields and replaces them with values form the sheet. In order to make it work you need to create a valid draft. A draft is valid if it contains at least one merge field.
MERGE FIELDS
A merge field is a text you put in message subject or message body. A merge fields must be always enclosed in double curly brackets like {{Name}} otherwise it will be ignored and treated as normal text. You can use white spaces as well as accented characters. Let's say we would like to create a draft for sending invoices.
Example
Subject: Invoice {{Invoice Number}}
Body: Dear {{Customer Name}},
please see the attached invoice with invoice number {{Invoice Number}} for {{Amount}}{{Currency}} which is due {{Due Date}}.
Thank you for using our services!
In the example above there are six merge fields defined. You can place merge fields in message subject as well as in message body. If a merge field is in a subject or in a body multiple times like the {{Invoice Number}} all occurrences will be replaced. Make sure you always enclose merge fields in double curly brackets!
Create your first draft
Now it is time to create your first mail merge draft. Go to Gmail and click Compose message. Add some merge fields in the body or subject and save the draft. Now you can load the draft in the add-on. Your next step will be mapping of merge fields to columns.
Prohibited Characters
If a merge field contains one of these characters the merge field will be ignored:
()]+*?|.$^\
Examples
Valid merge fields which will be recognized by the add-on:
{{First Name}}, {{First_Name}}
{{day}}, {{día}}, {{день}}, {{วัน}}, {{يوم}}
Invalid merge fields which will be ignored:
only single bracket or no brackets - {Name, {Name}, {{Name}
use of prohibited character in tag - {{First^Name}}, {{Name(1)}}