How to Send Mass Email Campaigns in Outlook: Step-by-Step Guide

How to Send Mass Email in Outlook
Alex Kachalov Alex Kachalov 25 october 2023, 14:38 176
For beginners

Outlook is one of the most popular email clients, and it can be used to send mass emails. Many wonder how to do that, and this article is here to explain the procedure. We’ll show you the exact steps to take for most effective results.

But before you start, note that sending mass emails via Outlook is not an ideal solution. The process is tedious, time-consuming, and risks exposing the personal email address of each recipient to all the recipients on the list. You’re better off using a dedicated email service provider (ESP) like UniOne.

How To Send Bulk Emails Via Outlook

Here are the five steps you take to send bulk emails via Microsoft Outlook.

Step 1: Write a Draft In Microsoft Word

Creating the draft for your email on Microsoft Word is more convenient than using Outlook. Microsoft Word is integrated with Outlook, so you can compose your text in Word and send it via Outlook.

If your draft contains images and GIFs, you can preview how they’ll look in an email. Click the View tab from the top menu ribbon and select Web Layout. This option will show exactly how your text would look for the email recipients

Step 2: Start Mail Merge

Once your draft is ready, you can select the Mail Merge option. This feature lets you send personalized documents to a list of individual recipients.

Click on the Mailings tab in the top menu and select Start Mail Merge underneath. This option has a drop-down menu, choose E-mail Messages.

Step 3: Choose Your Email Recipients

Choose Select Recipients under the Mailings tab, and you’ll see a drop-down list of options:

  • Type a New List
  • Use an Existing List
  • Choose from Outlook Contacts

Let’s explain how each option works.

  • Type a New List: This option allows you to enter all the recipients’ email addresses manually.
  • Use an Existing List: Import an existing list of email addresses from an external source, e.g., a CSV file.
  • Choose from Outlook Contacts: Choose the email recipients from your existing list of Microsoft Outlook contacts (aka your address book).

You can edit your address list by adding or deleting entries. When done, click OK to save the new list as a file on your PC. The list will be stored under \Documents\My Data Sources by default.

Step 4: Personalize Your Emails

Personalization involves using personal data about your email subscribers to send more targeted messages. For example, you can begin a message with “Dear [Subscriber’s first name]” or “A reward for [Subsriber’s first name].” Personalization makes recipients more willing to engage with your messages.

You can change the greeting line on your emails directly from Microsoft Word.

Look for the Greeting Line option under the Mailings tab. Here, you can personalize the first thing the recipient sees when they open your message. For example, it can be “Dear [Recipient’s First Name].”

You can also insert custom fields in your email. Find the Insert Merge Field option under your Mailings tab, and you can insert each field where they fit.

For example, your message can be like:

  • Dear «First Name», We are inviting your «Company_Name» to our upcoming event, and will be glad if you attend…

You can insert merge fields anywhere you’re comfortable with them.

Step 5: Finish & Merge Your Email

At this point, you have finished creating and personalizing your email, and it’s time to send it en masse. Click Finish & Merge > Send Email Messages under the Mailings tab. Add a subject line and click OK to send your message.

Congratulations! You have successfully sent a mass email using Outlook.

Outlook Limitations

Outlook was designed with individual communications in mind. It is aimed at individuals who send messages to a single recipient or for relatively few people within an organization. It wasn’t built for bulk email sending, where one person sends an email to hundreds or thousands of subscribers simultaneously.

Outlook’s capabilities as a mass email tool are limited in many aspects. The most important shortcomings, as compared to a dedicated email service provider, are listed below.

Editing Capabilities

Neither Outlook nor Word is a perfect tool for composing emails. The process takes more time and may yield poor results for complex emails which will look inconsistently in different email clients.

External ESPs usually offer specialized email composing tools that let you create eye-catching emails that customers are more likely to respond to.

Example of an eye-catching professional email

List Management

Outlook doesn’t make it easy to manage email lists. Imagine you have 400 addresses on your email list and counting, and you need to use a certain portion of this list to send a message. This process will be tedious and time-consuming.

In contrast, email service providers make it unbelievably easy to manage email lists. You can create signup forms and embed them on your website. Whenever someone adds their email address to the form, it automatically reflects on the email list managed by your ESP. You can easily add and remove subscribers to keep your list in good shape. You can also segment your lists and send more targeted messages with external ESPs.

Avoiding Email Blocklists

A good ESP ensures that emails from your address aren’t blocklisted. Email services may block addresses for several reasons, such as high spam complaints rate of the originating mail server, malicious-looking content, or using words associated with spammers.

At UniOne, we detect and eliminate any potential malicious actors from our network, ensuring they don’t affect anyone’s reputation. Our servers are safe and secure. You can also request a dedicated IP address to send messages from and retain absolute control over your reputation.


Outlook doesn’t provide sophisticated automated email tools. For example, you can’t create an email that gets automatically sent to a customer when they take a specific action on your website. But you can do that with external email service providers like UniOne.

External ESPs provide sophisticated email automation tools. Without lifting a finger, you can send automated messages to individual recipients, e.g., password change requests, login notifications, abandoned cart emails, etc. You can’t do that with Outlook; you must send every email manually.

Hiding Recipients

When you send mass emails on Outlook, you need to add all your recipients to the BCC: section. BCC stands for “Blind carbon copy”, which means that any addressee from this section will not be seen by others. In contrast, if you add your recipients to To: or CC: fields, the entire list will be visible to anyone who receives a copy.

However, if you use an ESP like UniOne, each recipient will see the message as if it were meant for them only. They can’t see the email addresses of other recipients of the same email.

GDPR Compliance

General Data Protection Regulation (GDPR) is a prominent data privacy regulation enacted by all countries under the European Union (EU). If you have a subscriber based in the EU, you must adhere to GDPR requirements, such as including an unsubscribe link in your emails and deleting a subscriber’s data at their request.

ESPs have built-in data privacy and security features to help customers comply with GDPR and other data regulations. If you’re using Outlook to send mass emails, you’re more likely to run afoul of these regulations and risk legal consequences.

Address Limits

Outlook caps the number of recipients you can email simultaneously at 500. This limit makes the app unsuitable for any serious business that wants to communicate effectively with customers. Most mid-size or large companies may have over 500 subscribers on the list, meaning Outlook is unsuitable.

You can use Outlook to send emails when your business is just starting. However, if you cross over 500 subscribers, you must find an alternative email marketing platform to communicate with them.

Deliverability Tools

Email delivery rate is the percentage of emails you send that reach the intended recipients’ inboxes. For example, if you send 200 messages and only 160 reach the recipient’s inboxes, your deliverability rate is (160/200 x 100%) = 80%.

Email service providers have built-in tools to measure and improve your email deliverability rate. For example, your ESP can help you detect and remove invalid addresses from your subscriber list. It can identify the email addresses that haven’t interacted with emails for a long time, and you’ll decide whether you need to delete them.

Outlook doesn’t come with deliverability enhancement tools, which leaves you at a disadvantage compared to using ESPs.


Email service providers let you analyze the A to Z of your emails. You can monitor vital metrics about your email campaigns and know where to improve. Examples of such metrics include:

  • Open rate: The percentage of subscribers who open your message after receiving it. 15 to 25% is a good email open rate; anything below this figure is a cause for concern.
  • Bounce rate: The percentage of your emails that get rejected for whatever reason, e.g., invalid address, spam complaints, etc.
  • Click-through rate: The percentage of subscribers who click at least one link in your email.
  • Click-to-open rate: The percentage of subscribers who click on a link after opening your email. Brands increasingly favor this metric over click-through rates.
  • Spam rate: The percentage of messages that entered the recipients’ spam folders instead of primary inboxes.
  • Conversion rate: The percentage of recipients who follow the suggested action in your email.

Outlook doesn’t provide a built-in analytics tool to help you monitor the above metrics. However, UniOne and other ESPs provide a dedicated dashboard to monitor these metrics.


Outlook's Mail Merge works for sending one-off emails to recipients. However, you can't automatically follow up on emails, which is needed if you're pitching and selling products.

If you’re using an email marketing platform, it’s easy to follow up on emails. You can set reminders, and the platform will automatically notify you when it’s time to send a follow-up message to a lead or customer.

Frequently Asked Questions – FAQ

How can I send group emails without showing recipients’ addresses in Outlook?

You can use the BCC box to hide the names and email addresses of people you email to. Follow these steps:

  • Open a new message.
  • Put your own email address in the To box.
  • Add the list of intended recipients in the BCC box.
  • Type your message and send it.

If the BCC box isn’t showing, click Message Options > Fields > Show BCC to unlock it.

What Is the Address Limit For Outlook Emails?

Microsoft limits its address list to 500 lines. You cannot email over 500 addresses at a time, which makes Outlook unsuitable for business email marketing.

What’s the Best Mass Email Alternative To Outlook?

There’s no single “best” alternative, as it depends on many factors. Any ESP will do a better job than Outlook. UniOne is the option we can recommend because it offers secure and reliable email services for an affordable price.

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