A definitive guide to sending bulk emails

All of us have received important communication, which is meant for all other subscribers of the company/brand as well. Did you know what they are called? Let’s introduce you to bulk emails or email blasts and understand what they are really.

What is a bulk email?  

Bulk email, as a feature, refers to sending an email to a large group of subscribers at once. It’s also known as mass emailing or sending an email blast. Bulk emails are mostly generic, with minimal audience segmentation. Some examples are:

Is bulk email the same as spam?

Bulk emails are often confused with spam because sending a large number of mails could appear to be a spamming act. However, there's a clear difference between the two. 

While a bulk email is sent to a large number of recipients, it doesn’t imply that the email is unsolicited. The recipients would have opted-into receiving the emails at some point. A spam email, on the other hand, is an email that the receiver never signed up for or has been sent by a non-trusted or low reputation source. An email can also be labeled spam by the inbox provider if it finds the email to be of low value or engagement to the recipient. 

Unfortunately, bulk emails can be considered as spam. In fact, the first-ever email marketing campaign sent by Gary Theurk was considered spam. Email service providers(ESP) are perpetually improving their spam filters to keep their user inboxes clean.

What are spam filters?

Spam filters detect unwanted, malicious emails or emails coming from a non-trusted sender. They ensure emails like these do not reach the inbox.

Spam filters are always evolving and take into account multiple points to assess every email. Based on this, the email is assigned a spam score. This score determines if the email should pass through the spam filter. Failing to pass through the spam filters also jeopardizes the chances of better email deliverability in the future. 

As mentioned before, bulk emails, if not written properly, can be considered as spam. After all the hard work of writing the email content and building the recipient list, you would want your email to make it to your recipient's inbox. It is, therefore, important to learn how to send bulk emails correctly.

How to send bulk emails without spamming?

You should plan your bulk emailing execution keeping spam filters in mind. Here are some ways of avoiding spam filters, sending emails that your subscribers like to read.

Keep your content clean and well-formatted. 

A simple and clear design ensures your emails can be read through quickly. Keep the text-to-image ratio in check. Image-heavy emails are considered red flags by spam filters. Improper formatting, such as all-caps, can also trigger some spam filters.

Add a plain-text version for your HTML emails. 

Sending an HTML email without a plain-text version signals spamming to email clients. Some ESPs do not support all HTML components and could render your emails distorted. By including a plain-text version, you indicate legitimacy to ESPs and also make them user-friendly. 

Avoid using shortened URLs or attachments.

Spammers often use shortened URLs for hiding the original website link from subscribers and tricking the ESPs. A shortened URL in your email could make it appear malicious, thereby landing in the spam folder.

Include an unsubscription link.

Always give your subscribers an option to unsubscribe from your mailing list. It should be visible, adequately placed, and have a link that works.

Keep a check on the To, Reply-to, and From fields.

Using the recipient's name in the To: field of your email instead of just their email address indicates that the recipient is acquainted with you. It increases the chance of your email not being labeled as spam. You can use merge tags to personalize the field.

Similarly, select a From: name that your subscribers will recognize easily. Using a person's first name, along with the company name, can help you appear more personalized - for example, John from Freshmarketer. The reply-to address you set for your email should be a real and functional email address. You should make it look more human.

Consider using a dedicated IP address.

If you send emails in bulk, it's recommended you get a dedicated IP address. Unlike a shared IP, you will have more control over your deliverability since this IP address is unique, and no other sender would be using it.

Use an SPF record and DKIM signatures.

An SPF record warrants your mail servers that no one else can send out emails from your domain. A DKIM signature ties the identity of the sender with the message, making it more trustworthy. Both of them are indicators of clean email practices. They bring down the chances of ESPs identifying you as a spammer.

Be in accordance with the CAN-SPAM act. 

In 2003, the US president GW Bush passed the the ‘Controlling the assault of non-solicited pornography and marketing (CAN-SPAM) act. It puts out specific guidelines that need to be followed by commercial emails and specifies penalties and fine when you violate them.

Making sure you are staying compliant with anti-spam laws while sending bulk emails will reward you well by helping you maintain good deliverability. A lot of people who understand the difference between bulk email and spams, often question whether transactional emails are also bulk emails. They aren’t.

The difference between bulk emails and transactional emails

Bulk emails

As mentioned earlier, bulk emails are a single email that you send to your entire list, which is not triggered by a user-event. The sender completely controls bulk emails. They can be emails on changes in terms and conditions, discount communications, product updates, etc. The main focus is mostly around delivery and effective communication. Bulk emails are primarily proactive in nature.

Transactional emails

Transactional emails, on the other hand, are critical business communications and are triggered by specific user actions. They are dependent on user behavior. Transactional emails are password reset emails, payment alerts, triggered notifications, support responses, and more. The main focus, in this case, is immediate delivery and landing in the priority inbox. They are one-on-one and are reactive in nature.

Improve your engagement with personalized bulk emails

In today’s world, while email marketing continues to evolve, everyone wants to receive personalized communication. 50% of companies feel that personalization increases engagement, and you can incorporate that into your bulk emails too. 

Clean and build focused email lists using the existing data at hand. Sort your first names, last names, company name, behavior patterns, etc. You can add merge tags in your email subject lines and within your emails, to talk directly to the recipient. 

With all this information at hand, you can also make decisions on who to send all the emails to. For instance, you have a new product update or discount. You want to send the email to your entire audience, but you should ideally clean your list and not send the email to subscribers who haven’t interacted with your emails in 3-4 months. This will eventually also improve your email deliverability and engagement rate. 

Now that you are personalizing your bulk emails a little bit, you can also focus on your email metrics, you should follow, and how you can measure the performance of your bulk emails.

Measuring the success of your bulk email campaigns

Doing email marketing the right way is a science by itself, with a lot of data points to learn from. Here are a few of those metrics you should track closely for every email campaign

Open rate

Open rate is the percentage of recipients who open your email, out of the people you send the email to. The open rate of your emails is a good comparative metric. Comparing open rates of two emails can help you understand what kind of subject lines and topics work with your subscribers.

Note: Most of the email marketing tools rely on the loading of images to determine if the email was opened. Since a lot of email clients block images, open rate is not a 100% accurate metric. It should be looked at in conjunction with the clickthrough rate. Usually, if an email receives a click, it is counted as open even if the images did not load.

Click-through rate (CTR)

Clickthrough rate is the percentage of recipients who clicked on at least one of the links in your email. Clickthrough rate is a key indicator of the relevance of your message for the subscribers. If your CTR is good, it means your email content is engaging and leads subscribers to take the next action.

Bounce rate

The bounce rate is the percentage of emails that failed to get delivered. A bounce could be a hard or a soft bounce. Hard bounces result from invalid, non-existent email addresses. These emails will never be successfully delivered and are returned to the sender. A soft bounce is a temporary non-delivery of email because of a full inbox or a problem with the recipient's server. The emails might be held up by the recipient's server and delivered later. 

Bounce rate might not be a direct indicator of your email performance but is a critical metric to track. You should regularly flush off bounces from your email list. Repeatedly sending emails to invalid addresses brings down the sender's reputation and impacts deliverability.

Unsubscribe rate

Unsubscribe rate is the percentage of the total recipients who unsubscribe after receiving the email. Your unsubscribe rate might not reveal the entire picture. A lot of subscribers who do not like your emails find the effort of unsubscribing even more tiresome and just ignore your emails. However, it is important to keep a check on it. A growing unsubscriber rate needs corrective actions.

But, the success of your bulk email campaigns is also driven heavily by the email delivery service you choose. You should not jump into execution without a proper evaluation of the email delivery services available.

Choosing a bulk email delivery service

A good bulk email delivery service should help you scale your email sending, deliver emails predictably to inboxes and make it easy for non-technical marketers to run campaigns. The following list will help you evaluate bulk email services better.


We're well past the decade when hitting the send button on your email campaign meant reaching your subscriber's inbox. ESPs today focus on keeping the user inbox clean by filtering off spam and unwanted emails. Your email delivery service should match these advancements and offer high deliverability. You should spend some time checking their existing customers, reviews, technical infrastructure, and authentication methods.

Customizable templates

Customizable templates help marketers become less dependent on designers and developers. An email delivery service should offer a library of templates to choose from - the more, the better. Marketers should be able just to pick a template, duplicate and customize it, and have it ready to send.

Easy-to-use editors

Creating emails becomes faster and convenient if your email delivery service offers a friendly editor. It should allow drag-and-drop of commonly used elements, inserting HTML snippets and merge tags for personalization. It should help you build an email that looks good across devices and screen sizes.


The obvious next step after you have launched your bulk email campaign is to track and analyze the performance. While evaluating an email delivery service, pay close attention to how detailed it can get when it comes to reporting. Alongside the basic metrics high-level data such as open rate and clickthrough rate, it should also allow you to go at the contact level and analyze if a particular contact opened, clicked, and so on. It's important because these numbers help you fine-tune your next campaign and audience segments.


Bulk emailing is a great practice if done correctly. If you understand the fine line between sending an email in bulk and spamming your recipients, then you can create incredible emails. With the rise of personalization, there are a lot of ways of making your bulk communication more targeted and effective. It helps you improve your ROI and keep your customers happy.