How to Set Up Mozilla Thunderbird to Send Mass Emails

Saikat Basu 30-06-2009

How to Set Up Mozilla Thunderbird to Send Mass Emails thumbnail10“Is there a way to send personalized bulk emails using Mozilla’s Thunderbird? That is sending mails to a group of people without each of them knowing about each other’s email address (without using BCC). Also, with each person having only his own mail address in the “˜To’ field.”


I expected this question after my previous post – How to Send Personalized Mass Emails in Outlook How to Send Personalized Mass Emails in Outlook With Mail Merge Read More . So, let me continue where I left off and do a bit of Mozilla Thunderbird add-on hunting. After all, Mozilla’s rich add-on universe has a cure for every conceivable “˜problem’ except world hunger.

Yes, I found the answer in It’s the Mozilla developers’ community dedicated to open and free, quality applications and extensions – a perfect place to check out when you want to know how to set up Mozilla Thunderbird for anything.

Mail Tweak is a Thunderbird extension for Thunderbird ver. 2.0+. It’s a collection of enhancements and workarounds for the email client. The enhancements total around 36 (113KB) and one of them is called Personalize messages.

How to Set Up Mozilla Thunderbird to Send Mass Emails 1 mail tweak enhancements

This ‘productivity’ tweak sends each recipient an individual message using fields from the address book or a CSV (comma separated values) file.

  1. Go to the installation page of Mail Tweak at Download the mailtweak-0.16.xpi file to your computer.
  2. Open Thunderbird. Select Tools – Add-ons – Extensions. Browse to the location of your downloaded file and install. Restart the Thunderbird client to complete.
  3. Open the Add-on window (from Tools – Add-on) and select the Mail Tweak extension. Click on Options.
  4. Scroll down the entries in the Tweaks section and select Personalize messages. Click OK.How to Set Up Mozilla Thunderbird to Send Mass Emails 2 options addons
  5. You can now compose a message by selecting Message – Personalize message from the menu toolbar.How to Set Up Mozilla Thunderbird to Send Mass Emails 3 message personalize

    Add your recipients (or a recipients list) as you normally do. You can include the contacts in other ways, of course.

    • Click on Address Book on the menu. Select the bunch of names – right click and choose Personalize from the context menu.How to Set Up Mozilla Thunderbird to Send Mass Emails 4 address book rightclick
    • Open a new message window from Message – Personalize. Select the Personalize button on the menu and pick up the mail addresses from a CSV file.
  6. To send the messages, click on File – Personalize (or click the Personalize button on the toolbar). An alert pops up with the option of “˜Send now’ or “˜Leave unsent’. With the latter option, Mail Tweak saves the messages (as individual emails) in the Unsent folder. After reviewing them you can email them from File – Send Unsent Messages.How to Set Up Mozilla Thunderbird to Send Mass Emails 5 compose send

Further personalize your email using Mail Tweak”¦


To include other fields like address, city, work phone etc. from the address book, specify field attributes in the emails. For example, to include the first name of each individual recipient – place a %%firstName%% where needed.
(All available address book field names are the properties as given in the nsIAbCard file. This is where all address fields of a particular contact are stored as attributes. Check out all the attributes here.)

Here’s an example to illustrate – to include the home address and the city of the contacts, include %% homeAddress%% and %%homeCity%% in the appropriate place. Similarly, it can be worked out for the other fields.


Without turning this into a soup of geeky codes and syntax, let me direct you to the Mail Tweaks Personal Messages section for some more help.


Although, Mail Tweak is built for the latest version, it can also be installed in Thunderbird 1.5 and in Shredder (pre-release versions of Thunderbird 3) with limited functionality. does put out this caution – Performance may be poor if you use this feature for large messages or many recipients, and you might see warning messages from Thunderbird. For bulk mailing, it is better to use a specialized bulk mailing program.

That’s a good advice but for a home user’s run-of-the-mill mass mailing needs using the Thunderbird client, Mail Tweaks is a good enough productivity solution.

So, how often do you use bulk mailing? Do you think this solution is workable for you? Let us know if you have any other freeware to lessen the load.


Related topics: Contact Management, Desktop Email Client, Email Tips, Mozilla Thunderbird.

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  1. Anonymous
    August 5, 2015 at 3:05 pm

    Has anyone used this facility since the last message in December 2014? I've tried downloading these files but they are either corrupted or I'm ot doing something I should be doing - coz it don't work! Please help - someone!

  2. sameer
    December 21, 2014 at 2:10 pm

    Is there any free software to send 100000 emails daily

  3. Azhar
    February 2, 2010 at 12:22 am

    Did this with the new mail tweak for thunderbird 3. Working fine, but with one problem- the mails i send using this add-on are all going to the spam folder. Any way to change that?

  4. Sarah
    September 20, 2009 at 10:41 am

    Gorgeous Post .. ;-)

    I don`t know if its good to ask this ....

    Can You give us a small tutorial on how to

    use dark mailer .. ???

    The software is able to send 500,000 e-mail

    messages per hour from a regular cable

    modem connection ...

    Here is Wikipedia Page :

    I got Version 1.38

    If Not Can You Email Me .. !!

    Seriously I am Appreciate The Great Knowledge

    in Your Awesome Blog ... GOD Bless You & Yours.

    • Saikat
      September 20, 2009 at 10:57 pm

      Wish we could, but Dark Mailer is not free. And we guys over here are dedicated to freeware :)

  5. Darryl
    September 16, 2009 at 11:48 am

    Can ThunderBird really handle sending out 2,000 e-mails at once?

    • Saikat
      September 16, 2009 at 11:02 pm

      The limit's also are determined by your email provider not only Thunderbird.

      • Cal
        December 1, 2015 at 10:04 pm

        My email provider allows me to send more than thousand emails at once however i dont know how to do it by Thunderbird? Can you please help me on that? thanks

  6. Jeremie
    September 11, 2009 at 1:49 am

    Thanks for this article, very usefull!

  7. marc
    July 22, 2009 at 10:54 am

    Thank you for this. I'm passing it along to a friend who can put this information to very good use.

  8. crac82
    July 6, 2009 at 8:18 am

    Here’s an example to illustrate

  9. Mida
    July 2, 2009 at 7:14 am

    is there any easier way to add 2000 email to Thunderbird?

  10. Bill
    June 30, 2009 at 9:14 am

    Can I send over 500 emails somehow from gmail or google apps?

    • Saikat
      July 2, 2009 at 1:01 am

      One way could to distribute your addresses in the CC and BCC fields. Another way is to upgrade your Google Apps account from the standard one. I am not an user of Google Apps so won't be able to advice you in detail. But check this [Broken Link Removed] in the Google Support forum.
      Hope this helps.