Cold Email · · 7 min read

5 Best Mail Merge Software for Email Marketers in 2024

If you’re looking to boost open and reply rates with personalization, then mail merge software is exactly what you need.

mail merge software

Personalizing email campaigns with hundreds or thousands of recipients would be time-consuming and near impossible to sustain without mail merge software. But mail merge does more than just add prospect names to emails.

In this article, we’ll cover:

  • What mail merge software is
  • The benefits of mail merge software
  • The top mail merge tools to scale your email outreach campaigns

Let’s get started!

What Is Mail Merge Software?

Mail merge is the term given to software that performs email personalization by automatically filling specific fields in an email with prospect names, titles, or company names. This data normally comes from a spreadsheet or prospect list that the software references to fill values in areas of the email referred to as mail merge variables, merge tags, or ‘attributes’.

Mail merge variables may differ from one software to another but typically are tagged with curly brackets like {{firstName}}.

Mail merge is most commonly used for personalizing emails but can also perform important tasks such as pulling data from spreadsheets to automatically fill in tracking numbers, product details, delivery addresses, and more.

Why Use Mail Merge Software?

While mail merge as a task is relatively simple, it achieves a lot more than just filling name tags in emails. Let’s take a quick look at what makes it an invaluable tool for email marketers.

Mail Merge Increases Deliverability and Avoids Spam

Email marketers send hundreds and often thousands of emails a day. Sending out hundreds of the same exact email mimics classic spam behavior and will definitely harm deliverability.

Mail merge allows marketers to mix up their large campaigns with personalized messaging. A message addressing a recipient by name is far more likely to reach their inbox and avoid being flagged as spam.

Mail Merge Improves Open Rates

Simply having a prospect’s name in the subject line can improve open rates by 26%. Compared to non-personalized subject lines, personalized ones have an average 50% higher open rate.

By improving open rates (and taking the right steps for email outreach), marketers can expect better response rates to follow.

Mail Merge Saves Time and Boosts Productivity

Manually personalizing only a few dozen emails would be an incredibly time-consuming and exhausting task. In contrast, mail merge software allows email marketers to personalize thousands of emails by filling in a few lines of variables.

Often mail merge software comes with a range of automation tools for follow-up sequences and notifications that overall can save you countless hours and let you instead focus on the things that matter most.

5 Best Mail Merge Software for Email Marketing

Now that we know how great mail merge software can be, here are our top picks of the best mail merge tools for email marketing.



Instantly is built to help you scale your outreach campaigns with optimal deliverability and seamless personalization. You can upload your prospect list from Google Sheets or as a CSV file and preset which data columns will fill your merge tags.


You can create your own email templates or use one of Instantly’s ready-made templates with a proven track record of results. Depending on the data in your prospect list, you can personalize emails with first names, locations, company names, and more.

But what if there’s a value like a prospect name missing from your list? Don’t worry, you can easily use Instantly’s advanced AI algorithms to take care of it.

Advanced Email Attributes

If a mail merge variable isn’t available for a lead you can either leave it empty or set a default value for such cases with a placeholder value. For example:

Hi {{firstName | there,}}

In the above example, ‘there,’ will be used if the variable ‘firstName’ isn’t available for a lead.

Looking for more variety? You can also insert more than one placeholder value and Instantly’s algorithm will randomly pick one, such as:

Hello {{firstName | there, | friend,}}

Using these placeholders to create variations is simple and allows you to generate even more diverse email bodies for your leads.

{{RANDOM | Hello | Hi | Greetings!}},

Randomizing subject headers and email bodies with these value sets will keep your email campaign full of unique emails and help you avoid getting flagged as spam.

Insert Custom Variables

There are endless options when it comes to personalization which is why you can use your own custom variables for your emails.

You can import Custom Variables that will show up in your email copy editor under the header name of your dataset. For example, if you have a column as ‘Title’ for prospects it will upload that as a Custom Variable, which you can later use in the copy as {{Title}} to dynamically insert the title of each contact.


After you upload your custom variables they will show up as options when you’re adding your variables in the email copy. Simply select the custom variable you want to use to insert in your email body.


Set Personalized Email Follow-Up on Autopilot

Once you’ve decided on your main email, you can create follow-up steps with the same or different set of mail merge variables. You can add as many follow-up steps as you like for your cold email outreach campaign.

You can schedule follow-ups for no-reply cases and set the number of days between each follow-up email. Once a prospect replies, they are automatically removed from the follow-up process.

Preview and Test Your Emails

Nothing is worse than starting a large-scale email outreach campaign with visible merge tags in place of your prospect’s names. Once your templates are ready you can preview any email in your sequence to see how it will look in action.

You can also send out a test email to an email address of your choice.

Instantly makes mail merge simple with its intuitive UI and set of automation tools. Interested to learn more how Instantly can help scale your lead generation and sales to new levels? Click here to find out!



Streak is a lightweight CRM extension for Gmail that lets users write personalized email sequences and manage replies. Part of its features is a mail merge tool that includes a scheduler for email campaigns and follow-up sequences.

Streak allows users to personalize messages with data from CSV lists and automatically follow up with prospects that do not reply. Once a prospect replies they are automatically removed from the follow-up list.

Key highlights:

  • Track and manage leads through a Gmail-based CRM.
  • Set automatic follow-ups for prospects that don’t reply.
  • Mail merge tool with CSV file support.



Similar to Streak, Mailmeteor is a mail merge tool built for Gmail that focuses on simplifying outreach. Users can create personalized campaigns and import prospect lists through Google Sheets. Mailmeteor is an option for small businesses interested in scaling their marketing campaigns in Gmail.

Key highlights:

  • Google Sheets support with mail merge tools to personalize fields.
  • Campaign builder that has an automatic follow-up option for recipients that don’t reply.
  • Suitable for small to medium-sized email campaigns that will be done through Gmail.

Yet Another Mail Merge


Another lightweight Gmail-based tool, Yet Another Mail Merge is as the name playfully implies a mail merge tool designed to make outreach simple. Prospect lists should be imported through Google Sheets with columns for each merge tag that will be included in the email body.

Templates are written in Gmail with the merge tags filled out where suitable such as {{}}. Similar to Instantly, users can track how well their campaigns perform with open and click-through rate analytics.

Key highlights:

  • Add personalized and custom merge tags.
  • Includes email metrics such as open and reply rates.
  • Lightweight but powerful Gmail-based mail merge tool.



Like Instantly, Klenty is a Sales Engagement Platform (SEP) with a range of email outreach tools, including mail merge. Klenty can incorporate emails from multiple email clients such as Outlook, Apple Mail, and Gmail.

Their mail merge tool has detailed personalization options such as image personalization that allows teams to attach custom images to emails such as rep profile pictures and website screenshots.

Key highlights:

  • Mail merge tool with image and video personalization options.
  • Simple interface to preview and edit email templates.
  • Email automation for auto-replies and follow-ups.
  • Google Sheets and CSV support with auto-import functionality for when lists are updated.

Key Takeaways

Mail merge is a crucial tool in any email marketing software. It saves valuable time, boosts productivity, adds personalization to your email outreach, and gets results at scale. When considering the right mail merge tool for email marketing, look for:

  • Google Sheets support for prospect lists and if mapping columns and values is simple and intuitive.
  • Multiple email provider support (Gmail, Outlook, business domain email).
  • Automated follow-up sequences with detailed scheduling options.
  • Custom and advanced mail merge variables that can easily be added to your subject lines and email body.

Check out how Instantly can be the perfect fit for your email marketing campaigns!

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