Sayl Mail - mail merge sample email
Copy the subject and message into a new email with mail merge turned on (or use Mail merge > Use the sample email text).

SUBJECT
Your October order summary, {{first_name}}

MESSAGE
Dear {{first_name}},
Thank you for ordering from us this month. Here is the summary for {{company}}:
Order total: {{order_total}}
Delivery to: {{city}}
If anything looks wrong, just reply to this email.
Regards,
{{my_name}}

BLANKS YOU CAN USE
{{name}}  Name column: the full name, e.g. Rahul Verma
{{first_name}}  first word of the name, e.g. Rahul (a First Name column works too)
{{last_name}}  rest of the name, e.g. Verma
{{email}}  Email Address column
{{company}}  Company column
{{city}}  City column
{{order_total}}  Order Total column
{{any_column}}  any other column: its heading in lower case, spaces become _ ("Due Date" -> {{due_date}})
{{my_name}}  your name (the sender)
{{my_email}}  your email address
{{date}}  today's date