How to send bulk emails: Gmail, Outlook, Excel or a tool

Have you ever pasted 200 addresses into the “To” field, hit “Send” and kept your fingers crossed? Almost all of us have been there.

And it almost always ends the same way: emails in spam, reply-all chains and no idea who opened it.

Quick answer: there are three ways to send bulk emails. From Gmail or Outlook with mail merge and an Excel list, if you’re sending a few hundred a day. With blind carbon copy (BCC), only for internal notices.

And with an email marketing tool once your list grows, because it adds the unsubscribe link, the statistics and the authentication that Gmail, Yahoo and Microsoft require.

In this guide, you’ll see how to do it with each option, step by step, and what to check so your emails reach the inbox.

What is a bulk email and when is it legal to send one?

A bulk email is the same message sent to many recipients at once, usually with some personalized data such as the name. A newsletter, an offer or a notice to all your customers are bulk emails.

Bulk doesn’t mean spam. The difference is permission.

In Spain, the LSSI prohibits sending commercial communications by email to people who haven’t requested or authorized them. The exception is your customers: you can write to them about products similar to the ones they’ve already bought, with an easy way to unsubscribe.

The GDPR adds another obligation: being able to prove that consent. That’s why it’s best to collect contacts with a subscription form and, even better, with double opt-in.

And purchased databases? Out of the question. On top of the legal risk, they’re full of addresses that don’t exist and spam traps.

3 ways to send bulk emails (and when to use each one)

Not all options are suited to the same job. What changes between them is the volume they can handle and what you know after the send.

Here’s a quick comparison:

1. How to send bulk emails from Gmail

With a free Gmail account, you can send up to 500 emails a day. If you go over that, Google blocks sending for a few hours. You’ll find the details in sending limits.

If your company uses Google Workspace (Business Standard or higher), you also have mail merge. Open “Compose”, add the recipients or link a Google spreadsheet, and turn on “Use mail merge”.

Then type @ to insert tags such as @firstname in the text. When you send, each person receives an individual email without seeing the others.

Google limits this feature to 1,500 recipients a day and adds an unsubscribe link at the end. For a small business with a small list, it works.

What you won’t get are open or click statistics. We explain it with screenshots in how to send bulk emails for free using Gmail. And we compare the results in Gmail vs. Mailrelay.

2. How to send bulk emails from Outlook with Excel

Word’s mail merge is the classic way to send a bulk email from Outlook. It combines three programs: Excel stores the list, Word writes the message and Outlook sends it.

Before you start, prepare your Excel file. Use one row per contact and one column per piece of data, with simple headings in the first row: “Name”, “Email”, “Company”. No merged cells or empty rows.

Then follow these steps:

• In Word, go to Mailings > Start Mail Merge > E-mail Messages.
• Click Select Recipients > Use an Existing List and choose your Excel file.
• Write the message and insert the fields with Insert Merge Field (for example, the name in the greeting).
• Check several contacts with Preview Results.
• Click Finish & Merge > Send E-mail Messages, choose the email column, type the subject line and send.

It does have its drawbacks, though. You need classic Outlook: the new Outlook for Windows doesn’t handle sends from Word properly. You also can’t add attachments or CC recipients, or find out who opened the email.

And the limits are still there. Outlook.com allows 5,000 recipients a day, and Microsoft 365 allows 10,000. These are mailbox caps, designed for people, not campaigns.

3. Why you shouldn’t use blind carbon copy (BCC)

Putting everyone in BCC keeps recipients from seeing each other’s addresses. But it’s the worst option for a bulk send.

An email with hundreds of hidden recipients is a classic spam signal for filters. You can’t personalize the greeting.

And if someone accidentally writes to you with regular CC, a single “Reply all” exposes the entire list.

Use it only for internal notices or small groups that already know you.

How to send a bulk email with a tool, step by step

When your list grows beyond a few hundred contacts, or you want to send every month, an email marketing tool saves you time and protects you from blocks.

It sends from properly configured servers, manages unsubscribes and tells you what worked. Below are the seven steps for your first send.

Step 1: build a permission-based list

Start only with contacts who have agreed to receive your emails: customers, subscribers from your website or event attendees. A small, engaged list performs better than a huge, cold one.

If you don’t have a list yet, start with a form on your website and a good reason to sign up, such as a discount or a free guide.

Step 2: import your contacts from Excel

Save your Excel file as a CSV file, with one column per piece of data. With most tools, you just upload it and say what each column is. We walk you through it in how to import contacts.

Take the chance to clean it up: remove duplicates, misspelled addresses and people who have already unsubscribed. That list hygiene protects your reputation from day one.

Step 3: authenticate your sending domain

Always send from an address on your own domain, not from a Gmail or Hotmail one. Then add the SPF, DKIM and DMARC records your provider gives you.

That way Gmail, Yahoo and Outlook know the emails are yours. You’ll find the full guide in sending domain.

Step 4: segment before you write

Writing to a customer of many years isn’t the same as writing to someone who signed up yesterday. Split your contacts into groups.

Also use custom fields for the city, the last product purchased or the language.

The better the message fits the person receiving it, the more clicks and the fewer unsubscribes. You’ll find ideas in segmentation in email marketing.

Step 5: design the email with a template

You don’t need to know HTML. Start from an email template and change the text, images and colors to match your brand.

Here are three of the templates in the Mailrelay editor, also available on the free account:

Take care with the subject line and the preheader: they decide whether the email gets opened. Include a single call to action and the recipient’s name where it sounds natural.

Here’s a bulk email template you can adapt:

Subject: {Nombre}, your 15% discount expires on Sunday

Preheader: For customers only. Apply it in one click.

Hi {Nombre},

Thank you for trusting us this year. As a customer, you get 15% off everything in the store until Sunday at 11:59 p.m.

No code needed: the discount is already in your account.

[See my discount]

Best regards,
Laura, from the Example Store team

Don’t want to receive any more emails? Unsubscribe here.

If you’re looking for more inspiration, here are 20 email marketing examples to copy.

Step 6: test before you send

Send yourself a test and open it on your phone and on your computer, in Gmail and in Outlook. Check the links, the images and the sender name.

If you can’t decide between two subject lines, run an A/B test on part of the list and send the winner to the rest.

Step 7: send, measure and improve

Schedule the send for when your audience usually reads their email. Then look at the results over the next 48 hours:

A bulk send is an experiment. Each campaign tells you something you can apply to the next one.

How to send bulk emails without landing in spam

This is the question we hear most often. The short answer: filters look at who you are, who you’re writing to and how your recipients react.

Since 2024, Gmail and Yahoo have required three things from anyone sending more than 5,000 emails a day. Authenticate the domain, offer one-click unsubscribe and keep the spam rate below 0.3%.

Microsoft has applied similar rules in Outlook and Hotmail since 2025. It’s explained in bulk sender requirements.

Here’s a checklist to review before every campaign:

• Authenticated domain with SPF, DKIM and DMARC, and a recognizable sender.
• Only contacts who gave permission, never purchased lists.
• Visible unsubscribe link and unsubscribes applied immediately with a suppression list.
• Clean list: remove bounces and contacts who haven’t opened anything in months.
• Gradual volume if it’s your first large send: start with your most active contacts.
• Balance between text and images, with no all-caps subject lines or excessive punctuation.
• Steady frequency, without jumping from zero to 20,000 emails overnight.

Want to know how mailbox providers decide? Here’s what Outlook, Gmail and Yahoo require to keep your emails out of spam.

And how spam filters work. It all adds up to your sender reputation and the deliverability of your campaigns.

Common mistakes when sending bulk emails

Some mistakes show up in almost every first campaign. These are the most common:

Sending from a free address. A @gmail.com sender that sends hundreds of promotional emails raises suspicion. Use your own domain.

Sending everything to everyone. Without segmentation, the message doesn’t fit anyone and unsubscribes skyrocket.

Forgetting the unsubscribe link. Besides being mandatory, if people can’t find it, they’ll mark you as spam.

Not testing. A broken link or a badly merged name (“Hi {Nombre}”) shows up in thousands of inboxes at once.

Jumping straight to a large volume. Mailbox providers are wary of sudden spikes from a new domain.

Sending without looking at the results. If you don’t check opens, clicks and unsubscribes, you’ll repeat the same mistakes in your next campaign.

How Mailrelay helps you send bulk emails

With Mailrelay, you can send up to 80,000 emails a month to 20,000 contacts with the free account, with no daily limit. For most small businesses, that’s enough to get started.

You import your list from a CSV file in minutes and organize it into groups and segments. The drag-and-drop editor comes with templates and AI-assisted writing.

We also help you set up your domain with SPF and DKIM, and automatic cleaning removes bounces. Every send includes its unsubscribe link, and you get real-time statistics with a click map.

And if you get stuck? Support is human, by chat, ticket and phone, on every plan, including the free one. You can see what each plan includes on our pricing page.

Conclusion: choose the route that fits your list

If you send a few hundred emails now and then, Gmail or Outlook with mail merge is all you need.

If your list is growing or you want to know what works, switch to an email marketing tool before you run into deliverability problems.

Either way, the rule is the same: write only to people who have given you permission, from your own domain and with an easy way to unsubscribe. If you want to keep learning, here’s how to create a mailing from start to finish.

Frequently asked questions about how to send bulk emails

These are the questions people ask Google and AI assistants most often.

Can you send bulk emails for free?

Yes. Gmail allows 500 a day with a free account, and some tools have free plans.

With Mailrelay, you can send 80,000 emails a month to 20,000 contacts without paying, with statistics and support. You’ll find a comparison in free bulk email software.

How many emails can I send a day from Gmail or Outlook?

Free Gmail, 500 recipients a day; Google Workspace, 2,000 (1,500 with mail merge). Outlook.com, 5,000, and Microsoft 365, 10,000, with a maximum of 500 per message.

How do I send personalized bulk emails?

Add one column per piece of data to your list (name, company, city) and tags in the text that are replaced in each email. Word and Gmail mail merge can do it, as can any tool with custom fields.

How do I send a bulk email without recipients seeing each other?

With mail merge or an email marketing tool: each person receives an individual email. Blind carbon copy also hides the addresses, but it doesn’t personalize and filters distrust it.

How do I send bulk emails from Excel?

With Word and Outlook: use your Excel file as the list in “Mailings > Select Recipients”. If you use an email marketing tool, save the Excel file as a CSV and import it.

Is it legal to send bulk emails?

Yes, if you have the recipients’ prior consent or they are customers to whom you’re offering products similar to the ones they bought. Each email must identify the sender and include an easy way to unsubscribe.

Jose Argudo

CMO at Mailrelay. Writes about email marketing, copywriting and conversion for small businesses and entrepreneurs.

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