Mail Merge Explained

On October 31, 2019
8min read
Piotr Malek Technical Content Writer @ Mailtrap

Can you imagine being a VP at a large corporation and reaching out to each of your customers directly? Bankers or insurance associates do it all the time, and somehow, they manage to personalize each of the thousands of messages they send. Are they superhumans? Some might be, but most of them probably just use a good ol’ mail merge feature. 

What is mail merge?

Mail merge is a method of building personalized letters or emails with a bit of automation. It requires two components: 1) A template of a letter or an email with specific placeholders in the body, and 2) A spreadsheet with a set of data that should replace placeholders for each individual recipient. These can be names, addresses, or any other custom data. Some tools even allow for sending individual attachments with emails.

A mail merge functionality combines these two components into one piece – a personalized message with data relevant for you and you only.

What are the uses of Mail Merge?

Mail merge has been in use for many years, even before the internet changed how we do many things. It’s become omnipresent in the offline world, as a matter of fact.

Very often, when you receive a letter from a company or an institution, you’ll see your name and address printed on it. It will often start with “Dear John,” unless your name is Suzie, then you’re likely to see “Dear Suzie.” In the body, you’ll find some seemingly personalized references to your actions or further mentions of your personal details. In many languages, you’re likely to see gender-specific expressions.

The same goes for emails. Whenever someone reaches out trying to sell you something, their email will probably look like this:

Another email from this series would look something like this:

And it can go on for thousands of emails sent within just minutes. No one would bother writing each of these emails and inserting details one by one. Instead, they delegate these mundane tasks called mail merge. At the same time, since the emails look fairly personal, they have a higher chance of convincing a recipient to take the desired action.

A user of mail merge doesn’t necessarily need to be pretending to be personal. This functionality is also often used in invoices, bank statements, on envelopes, and in dozens of other places. Check the mail you have received lately, and you’ll find plenty of examples.

One thing John had to figure out was the proper tool to use mail merge with. There’s no shortage of options, luckily.

Which tools to use with mail merge?

Offline usage 

With offline in mind (letters, envelopes, paper invoices, etc.), it’s safe to say Microsoft, with its Office / Office 365 products, has been the most popular choice for many years. To create and print hundreds of personalized materials, all you need are Microsoft Excel and Microsoft Word. 

You create an Excel spreadsheet with the list of records to be inserted into your templates. Simultaneously, you build a template in a Word file and merge both files. MS Word will generate all your files within seconds. 

Check Microsoft’s step-by-step guide to mail merge in Excel and Word in their documentation.

There’s several add-ons for Microsoft Word that let you use mail merge with attachments, format the customizable text, or add individual, visual elements. Check out Mail Merge Toolkit 4.2, for example.

Online usage

With the abundance of available options, online usage of mail merge is a far more extensive topic. We’re going to focus on it for the rest of this article.

As you may expect, MS Excel and MS Word are good not only for printed letters and invoices but also for emails. This is when Microsoft Outlook comes into play. And it works in a very similar fashion. You set up a data source in Excel, create a mail merge-inclusive template in Word, and send newly created emails via Outlook (Gmail could work too). Check out Microsoft’s tutorial here.

If Microsoft’s environment isn’t really your thing, there are several other options. If you use Gmail, there are many add-ons that let you use Google Sheets as a source and Gmail as a tool for composing and sending emails. We’ll talk more about the most popular tools below. 

You can also add mail merge without using 3rd parties but with Gmail API instead, here’s how to do it.

Most, if not all, platforms for sending mass emails also offer mail merge. They just might not call the feature that exact name. Instead, you might find references to custom or dynamic fields or even to snippets. Regardless of the naming, it’s all the very same thing. The functionality can often also be replicated with various APIs without any trouble.

Should I use a plugin or a platform for mail merge?

The choice of an online tool for mail merge really depends on your use case. If you’re more of a casual sender and don’t send more than 50-100 emails a day, you’ll probably be better off with a simple plugin. This way, you can get everything you need in a simple interface, sometimes even without extra expenses. We’ll introduce below a few Gmail add-ons, but you can also find tools for other popular email clients.

If you, however, send newsletters, transactional emails, or other forms of mass emails – you’ll need more than that. Email clients enforce strict limits on the number of emails sent and offer limited capabilities. Sending high volumes from a Gmail or even a Google Apps account will also look suspicious to spam filters and will likely hurt your deliverability.

If you plan to send thousands of emails, you need to use a dedicated tool for sending mass emails. As we mentioned before, nearly all of them offer mail merge-like functionality so you can personalize each of your emails momentarily. If you’re looking for a transactional email provider, check out our guide to the best platforms of this type.

But, if you don’t have the time to go through another blog post and want just a quick recommendation, no worries, we’ve got you covered.

Mailtrap Email API is a reliable sending solution of the Mailtrap Email Delivery Platform that can send your transactional emails from any application.

The solution is geared toward devs and QAs who want to gain more control over their email deliverability and make sure their emails reach recipients’ inboxes.

Mailtrap Email API offers actionable analytics which enable you to find and fix sending issues early and consist of timely deliverability alerts, up to 60 days of email logs, webhooks, and critical metrics dashboards.

What’s more, if you ever need to dig deeper into your email performance data, Mailtrap Email API will allow you to do so through filtering by domain, mailbox provider, and/or email category. 

Other features of the sending solution include a sending throughput of up to ~10,000 emails/second, dedicated IPs, auto IP warmup, and suppression lists available to users after a straightforward setup/migration process. 

To learn more about Email API, check out the video below:

Which tools to use for mail merge in Gmail?

As we talked about earlier, there’s a way to use Gmail with MS Word and Excel. But first of all, it’s far from straightforward and second, it makes you dependent on other tools. For that reason, various Gmail add-ons are far more appealing options. Here are the most popular user choices:

GMass is a popular plugin for Google Chrome that enables mail merge capabilities. And it does much more than that. Not only can you quickly set up personalized emails to your recipients, you can also schedule them to be sent at a specific time and set up automatic follow-ups to be sent if no reply is received. GMass also allows for tracking opens and clicks, so it makes a pretty decent cold email platform.

Another popular choice is Mailmeteor. This plugin also offers a chance to personalize emails and send even 1,5000 of them in a single day! Like the previous entry, it also comes with email tracking functionality. On top of that, each email can be previewed to avoid any trouble (and trust us, errors happen).

Then there’s YAMM but it’s not just Yet Another Mail Merge. As the creators claim, it’s “the world’s most popular Google Sheets add-on for Gmail and G Suites users”. It comes with all the features of the other tools, such as email tracking and scheduling. Users can also use mail merge with individual attachments. And there’s a bunch of advanced features, such as individual, clickable links or pre-filled forms. Pick whatever you like!

MergeMail is also a similar tool that, to no surprise, is used for mail merge in Gmail. It comes with a standard set of features for personalizing and tracking emails. Its users can take advantage of various email templates and integrations available via Zapier.

What’s interesting, the first three tools we mentioned also offer support for cc and bcc fields. This can prove especially useful for salespeople out there. Frequently, they send mass campaigns to hundreds of leads at the same time. Rarely, though, there’s just one account manager responsible for each of these prospects. With cc/bcc in mail merge, they can add respective managers and/or their team leaders only to specific emails.

 Updating our earlier data source:

Mike as a team leader could be bcc’ed on multiple emails (invisible to customers) while the rest of the crew would be split between emails and placed in the cc fields. Each plugin would add the right contacts to the right fields. Awesome, huh?

Steps in creating a simple mail merge

Regardless of the software you use, creating a simple mail merge is usually a piece of cake. To visualize the process, let’s look under the hood of one campaign. 

As a data source, we can use the same spreadsheet we mentioned moments ago, let’s just skip the cc/bcc fields to make it even simpler:

We’re going to use GMass for the purpose of this tutorial but you’ll get very similar results with the other tools we mentioned too.

First of all, add GMass plugin to your Chrome and connect it with your Gmail or Google Apps account.

Then, hit the spreadsheet button to the right from the search box on top of your Gmail page and connect the spreadsheet that contains your contacts – including their name, email address, and any other details you need.

Gmail will automatically load a new email message l populate its ‘to’ field. You can then write or paste a draft of a message and personalize it with various fields from your spreadsheet.

Here’s a draft of a message we’ve sent before in a raw version:

All you have to do now is hit the ‘GMass’ button and wait for a few seconds. Emails personalised with mail merge will be sent.

For the record – GMass sent just one email to each recipient. The ‘2’ digit next to each conversation also includes an automatic ‘email couldn’t be delivered’ autoresponder that came right after. domain doesn’t accept incoming mail.

Test your mail merge setup with Mailtrap Email Sandbox

Last but definitely not least – don’t forget to test your mail merge emails before they’re sent to customers.

Why? Well, there is a big chance that you have personally received (probably more than once) an email with a {NAME} placeholder that somehow didn’t fetch the right data. 

For salespeople, this could jeopardize a chance of striking a major deal. For others, this could ruin a good first impression and completely distract recipients from a call-to-action.

The good news is that some platforms/tools that do offer mail merge also offer features for previewing emails before they’re sent. But, if you are a user of a platform/tool that does not, or simply skip the previewing process altogether, you will find out if something is wrong with your email only when it’s already too late. 

To prevent the situation described above, make sure you use a dedicated tool for testing emails.

Mailtrap Email Sandbox is a great option when it comes to email testing tools and is also part of the Mailtrap Email Delivery Platform.

Email testing with Email Sandbox is straightforward as well as secure and comes with no risk of spamming recipients in the process. This is the case as Email Sandbox captures all SMTP traffic from staging and dev environments, so you can then inspect and debug the emails.

The testing tool saves time since it’s much quicker to set up than an SMTP server, and it automates the whole email testing process. Plus, as Email Sandbox removes the need to manually test  with your personal inbox, your domain reputation doesn’t get affected.

Users of the tool get access to a range of features, including:

  • Multiple inboxes – create an inbox for each project/stage of a project
  • Spam analysis – check the spam score of your email content
  • Blacklist reports – check if your sending domain is present on any common blacklists 
  • Tech info – see the original SMTP transaction details and header values
  • Email forwarding – forward your testing emails to whitelisted recipients manually or automatically
  • Email preview – check how popular web browsers render your email
  • HTML/CSS check – see the support popular email clients have for your emails’ HTML/CSS code and any problematic (unsupported/partially supported) elements

The last two mentioned features will especially come in handy for testing your mail merge emails, and you can find them in the HTML and HTML Check tabs under Sandbox in your Mailtrap account

To start testing with Email Sandbox, all you have to do is create an account and complete a quick 5-minute setup described in detail in the getting started guide. So why not try it out?

Article by Piotr Malek Technical Content Writer @ Mailtrap