People who used to use MS Outlook, know how to make mail merge to send each individual mail to people in the list.
But for an opensource software as Thunderbird, it’s impossible without an additional plugin to do it.
So I introduce you for an add-on that may help called: Mail Merge (now it’s in v1.4.0).
You can find it via searching an add-on from Thunderbird Tools menu, add-ons or download from following URL: https://addons.mozilla.org/en-US/thunderbird/addon/47144/ that has also the instruction how to use.
Mail Merge - Personal Mail
Mail Merge has two solutions: Mass Mail and Personal Mail sending.
Personally, I found Personal Mail feature is a great one to use as we can send mail from csv file so that we can export the contact from other applications in CSV format and use the variable of CSV file head as pattern to put.
I extract here the instruction from add-on page above:
Mass Mail:
With “Mass Mail” you can create one mail for each recipient from a draft! Write a New Message; add all recipients to To; add Subject, Body and Attachments; click “File -> Mass Mail”. For each recipient a new mail is created automatically and stored in “Local Folders -> Outbox”. Ready to send: “File -> Send Unsent Messages”Personal Mail:
With “Personal Mail” you can create one mail for each record in a CSV from a draft! Write a New Message; add the Variable to To; add Subject, Body and Attachments; click “File -> Personal Mail”. You have to answer some questions (CSV, Character Set, Field Delimiter, Text Delimiter). For each recipient a new mail is created automatically and stored in “Local Folders -> Outbox”. Ready to send: “File -> Send Unsent Messages”
Please find example in add-ons URL of Mail Merge