How to Send Mass Emails in Outlook Without Going To Spam (2025 Guide)

Sending mass emails in Outlook can be a game-changer for businesses, marketers, and professionals. However, one of the biggest challenges is avoiding spam filters and ensuring high email deliverability.

In this guide, you'll learn:

✅ Best practices to send bulk emails in Outlook without getting flagged as spam

✅ Instructions on how to send mass emails efficiently

✅ How Charge and other tools improve email outreach

Why Do Outlook Emails Go to Spam?

Before diving into solutions, it's essential to understand why emails end up in spam. Here are some common reasons:

1. Spam Trigger Words in Subject Line & Email Content

❌ Words like "Free," "Act Now," "Limited Time Offer," and excessive use of exclamation marks (!!!) often trigger spam filters.

2. Sending Too Many Emails at Once

❌ Outlook limits mass emails to prevent spam abuse. If you exceed sending limits, your account may be flagged or blocked.

3. Using a Non-Business Email Domain

❌ Sending bulk emails from @outlook.com rather than a business domain (e.g., yourbusiness.com) increases the risk of being marked as spam.

4. Missing SPF, DKIM, and DMARC Authentication

❌ If your domain lacks correct DNS records configuration, recipient servers may reject your emails.

5. Low Engagement Rates (Spam Complaints & Bounces)

❌ If recipients don't open or interact with your emails, Outlook may categorize them as spam over time.

How to Send Mass Emails in Outlook Without Going to Spam

Follow this short guide to send bulk emails effectively:

Step 1: Use an Outlook Add-in for Bulk Sending

Microsoft Outlook was not designed for bulk email campaigns, so using a dedicated mail merge add-in is essential.

Charge for Outlook is the top choice due to its set of features that makes sending mass emails in Outlook smooth:

1) Seamless Outlook integration, so it will be easy to send bulk emails from Outlook;

2) Advanced personalization with variables, so emails will not be generic (non-generic emails are less likely marked as spam);

3) Sending delay settings;

4) Reply rates tracking and analytics.

Step 2: Personalize Emails to Improve Deliverability

Spam filters don't like generic bulk emails and mark them as spam. Personalization helps avoid this.

Best Practices for Email Personalization:

1) Use the recipient's name in content, especially in greetings.

2) Reference company name or past interactions.

3) Write unique content for different audience segments.

‍

Example of a Poor Email (Likely to Go to Spam):

Subject: Free Offer Just for You!!! 🚀

Body: Hello, we are offering exclusive discounts for a limited time. Act now before it's gone!

‍

Example of a Well-Optimized Email (Better Deliverability):

Subject: {First Name}, Here’s an Invitation Just for You

Body: Hi {First Name}, I noticed you recently signed up for our newsletter. I wanted to personally invite you to try our newest feature, which I think would be valuable for {Company Name}.

‍

Note: Charge automatically inserts data for better personalization, so you just need to select a variable and insert it in your content.

‍

We recommend using Folderly spam words checker - a free AI tool that checks your content on spam words and highlights it so you can significantly improve your content removing spam words from it.

Step 3: Set Up SPF, DKIM, & DMARC for Your Domain

Email authentication ensures that Outlook recognizes your domain as a trusted sender.

Email Authentication Keys in Simple Words:

1️⃣ SPF Record – Prevents spoofing by authorizing which mail servers can send emails to your domain.

2️⃣ DKIM Record – Adds a digital signature to verify email authenticity.

3️⃣ DMARC Policy – Prevents unauthorized use of your domain to send emails.

Where can you explore if everything is ok with your domain authentication?

• We recommend using Inbox Insights, which is a free tool for email deliverability testing. Just send emails to seed accounts from your mailbox, and you will receive detailed reports about your email deliverability.

Where can you generate DNS records for your domain?

• We use these SPF and DMARC generators because they are fast and easy to use, delivering results to your mailbox in minutes.

Step 4: Properly Manage Your Contact List

A clean email list reduces bounce rates and improves deliverability.

Best Practices for Managing Email Lists:

1) Use CSV files for bulk uploads and sendings. It's just comfortable.

2) Remove duplicate contacts to prevent sending the same content twice or more to one person. While this is a simple error, it is strange behavior. Imagine you are a recipient of these, and you are likely to mark your email as spam if it doesn't make a spam filter

3) Verify email addresses before sending. We highly recommend not just using verification tools but sending test emails from other non-main email addresses to your recipient's list and checking them for bounces (luckily, some email verification tools have this feature out of the box).

4) Segment lists are based on customer behavior, ESP, or other parameters, so your content fits the segment’s pain/interest.

Step 5: Follow Outlook’s Sending Limits to Avoid Blocking

Outlook limits the number of emails you can send per day.

The daily sending limit for warmed-up mailboxes is 200-300 emails per day. A minimum of 3 minutes of sending interval between emails is recommended to prevent Outlook spam filters from marking your emails as spam.

Start with small limits like 20 emails for new mailboxes, and grow it daily to 200 emails. It's a must-have action.

How Charge Helps You Send Bulk Emails Without Land in Spam

1) Email Personalization – customize emails with recipient details.

2) Smart Sending – Prevents spam by sending emails with delay & scheduling emails for best engagement.

3) Analytics & Tracking – Monitors reply rates and bounces.

Conclusion

Sending mass emails through Outlook comes with challenges - especially avoiding spam filters. By following the steps outlined in this guide, you can greatly improve your chances of avoiding spam filters and increasing email deliverability. In the next article we'll share more detailed info about outreach best practices in Outlook.

FAQ

Q1: Why do my emails keep landing in the spam folder?‍

Common reasons include using spam trigger words in the subject line, sending too many emails at once, using a non-business email domain, missing domain authentication records like SPF, DKIM, and DMARC, and low engagement rates. Addressing these issues and following the best practices in this guide can improve your deliverability.

Q2: What is the best way to send bulk emails from Outlook?‍

Use an Outlook add-in like Charge for Outlook to streamline the process. It allows for advanced personalization, sending delays, and tracking analytics, reducing the likelihood of your emails being marked as spam.

Q3: How can I personalize my emails to avoid spam filters?‍

Personalization is essential. Use the recipient's name, reference their company, and tailor your content to their past interactions or interests. Charge can automatically insert details like the recipient’s name and company name to make this process easier.

Q4: What are SPF, DKIM, and DMARC, and why are they important?‍

SPF, DKIM, and DMARC are email authentication protocols that help verify your emails as legitimate, reducing the chance they’ll be marked as spam.

Q5: How many emails can I send in Outlook without being flagged as spam?‍

Outlook limits how many emails can be sent per day to prevent abuse. For warmed-up mailboxes, the limit is typically around 200-300 emails per day, with at least 3 minutes between each email. Start with smaller limits and gradually increase them to stay within safe boundaries.