What Are the Dos and Don’ts of Sending Bulk Emails in 2025?

I’ll be straight with you — sending bulk emails isn’t as simple as hitting “send” to a long list of contacts.

What worked for someone sending a weekly newsletter might completely fail for your cold outreach campaign and vice versa.

You can’t keep experimenting to find out what works. That’ll waste a lot of resources, and besides, one wrong move can damage your sender reputation and get you blacklisted.

That’s why in this blog, I’m going to break down exactly what to do and what to avoid when sending bulk emails.

Additionally, I’ll also share the tools that can help you get it right from day one.

Keep reading!

TLDR: What You Should And Shouldn’t Do When Sending Bulk Emails

In a hurry? Here’s a summary you can read in 30 seconds.

What Should You Do When Sending Bulk Emails?

If you want your bulk emails to be successful, that is:

• Land in the primary inbox
• Get opened
• And get replies or clicks

Then you need to follow a set of practices that protect your sender reputation, keep you compliant, and make your emails worth reading.

Here are a few “Should Do’s” I have learned from experience (and from watching what actually works):

1. Set up proper sending infrastructure (SPF, DKIM, DMARC)
2. Warm up your email account before sending
3. Personalize your emails beyond just the name
4. Make it easy for people to unsubscribe
5. Use a reliable bulk email tool instead of free inboxes
6. Stick to a consistent sending schedule
7. Monitor inbox placement and postmaster reports

1. Set Up Proper Sending Infrastructure (SPF, DKIM, DMARC)

The first and most important step you need to take before sending bulk emails is setting up SPF, DKIM, and DMARC records for your domain.

What are these?

• SPF (Sender Policy Framework) tells email providers which servers are allowed to send emails on your behalf.
• DKIM (DomainKeys Identified Mail) adds a unique digital signature to each email, so the receiving server can confirm it really came from you and wasn’t altered in transit.
• DMARC (Domain-based Message Authentication, Reporting & Conformance) is the policy that enforces SPF and DKIM checks. It also sends you reports so you can see if someone is trying to spoof your domain.

As of February 2024, Gmail and Yahoo have made email authentication mandatory for bulk senders.

If you’re sending more than 5,000 emails a day, you must have these records correctly set up or your emails will be rejected outright.

I recommend setting up these records, even if you are not sending a large volume of emails.

It will help you build trust with email service providers (ESPs) from day one!

I have a detailed blog on How to Easily Set Up Your SPF, DKIM, and DMARC Records. Be sure to check it out.

2. Warm Up Your Email Account Before Sending

The next crucial step after setting up your email authentication is to warm up your email account before you start sending bulk campaigns.

Here are 2 reasons:

1. If you have a new email account, you would have not yet established trust (sender reputation) with mailbox providers. So, starting with a large sending volume will make you look suspicious, which can quickly push your emails into spam or get your account blocked.
2. If you are using an old email account, even if the account has a history, a sudden spike in volume can still trigger filters.

By warming up, you gradually increase your sending volume in a way that feels natural to ESPs.

So, regardless of the purpose, always warm up your email accounts before sending.

It’s one of the simplest ways to protect your sender reputation and maximize your chances of landing in the inbox.

3. Personalize Your Emails Beyond Just the Name

If your idea of personalization is just adding the first name, last name, and company name, you’re barely scratching the surface.

Real personalization is about making the recipient feel like the email was written specifically for them.

Here’s how you can do it:

• Reference a recent achievement, announcement, or milestone from their company.
• Mention an industry trend, challenge, or opportunity relevant to them.
• Point to content they’ve published or interacted with, like a blog post or LinkedIn update.
• Adapt your pitch or offer to match their role, goals, or current priorities.
• Use location-based details if it makes your message more relevant.

Moreover, by personalizing your emails, you show ESPs that you’re not blasting the same generic message to every contact on your list.

This helps you avoid triggering spam filters and reduces the risk of getting blacklisted.

4. Make It Easy for People to Unsubscribe

ESPs like Gmail, Outlook, Yahoo, and others have made it mandatory for bulk senders to include a visible, functional unsubscribe link in every email.

This is more of a compliance requirement, so make sure you place the unsubscribe option where recipients can easily see it.

Keep it simple and one-click.

The easier it is for people to opt out, the less likely they are to mark your email as spam, which protects your sender reputation and improves deliverability.

5. Use a Reliable Bulk Email Tool

The right bulk email tool can help you go a long way in making sure your messages actually reach the inbox.

A good tool will help you:

• Guide you through SPF, DKIM, and DMARC setup so mailbox providers trust your domain.
• Warm up your email accounts and help avoid deliverability issues.
• Track and monitor inbox placement and your sender reputation.
• Handle bounces automatically.
• Personalize at scale so every email feels one-to-one.
• Stay compliant with privacy and other regulations.

If you’re into cold emailing, check out these 7 Best Cold Email Software to see which tool is the best fit for your outreach.

6. Stick to a Consistent Sending Schedule

One of the factors ESP algorithms use to detect suspicious activity is your sending pattern.

If you’re blasting bulk emails in huge volumes one day and then going completely silent for weeks, it raises a red flag.

Here’s what you should do instead:

• Pick a sending frequency (daily, weekly, or monthly) and stick to it.
• Spread your emails out during the day instead of sending them all at once.
• Leave a short delay (30–90 seconds) between each email to make your sending look natural.
• Increase your sending volume gradually if you’re scaling up.

All this makes you look human and less like an automated spammer.

Note: Doing this manually can be tedious and error-prone, which is why I recommend using a good bulk email tool.

7. Monitor Inbox Placement and Postmaster Reports

Knowing where your emails are landing and how effective they are at getting opens, clicks, and replies is just as important as sending them in the first place.

Without visibility into metrics like:

• Inbox placement
• Domain and IP reputation
• Spam complaint rates
• Bounce rate
• Authentication pass/fail rate

…you’re essentially guessing about your deliverability.

You should be using email deliverability tools to test inbox placement before sending at scale and to keep an eye on your sender reputation over time.

Now that you know what to do when sending bulk emails, in the next section, I’ll share what you shouldn’t do.

What You Shouldn’t Do When Sending Bulk Emails?

Just as there are proven steps that help your emails land in the inbox, there are also mistakes that can instantly tank your deliverability.

Avoiding these is just as important as following the best practices we covered earlier:

1. Buy email lists from unverified sources
2. Overload your email with links or images
3. Use spammy and promotional words
4. Use misleading subject lines to boost opens
5. Send the same email to every segment without tailoring
6. Not cleaning your email list

1. Buy Email Lists From Unverified Sources

You might think this is the shortcut to building a proper email list quickly, but buying email lists, especially from unverified sources, always backfires.

Why?

Because these lists are often:

• Outdated and full of invalid email addresses
• Loaded with spam traps that can get your domain blacklisted
• Collected without consent, which can put you in violation of privacy laws
• Low quality, with recipients who have zero interest in your emails

So what should you do?

If you’re sending marketing bulk emails like newsletters, promotions, or event invites, build your list organically.

Whereas, for cold emailing, source your contacts from verified data providers.

This way, you can avoid email bounces, reduce spam complaints, and protect your sender reputation.

2. Overload Your Email With Links or Images

Having a lot of aesthetic elements might make your email look visually appealing to you, but to ESPs, it can be a red flag.

This is what most spammers and phishing emails do: they pack messages with flashy images, excessive links, and little meaningful text to lure clicks.

So what should you do?

• Keep your design clean and balanced
• Limit links to only what’s essential
• Maintain a healthy text-to-image ratio (around 60:40 text to visuals)
• Add descriptive alt text for images so your message is still clear if images don’t load

Note: For cold emails, completely avoid attaching images and links, and keep your emails plain text.

3. Use Spammy and Promotional Words

The easiest way to land in the spam folder or the promotions tab is to stuff your emails with pushy, overused sales terms.

Words like:

• Free
• Buy now
• Limited time offer
• Act fast
• 100% guaranteed

And more are used by spammers and other malicious senders to create a sense of urgency and lure clicks.

So, stay clear of words like these if you want to avoid the spam folder.

Similarly, avoid promotional language, because if you do, you’ll end up in the Promotions Tab.

Also Read: How to Avoid Gmail Promotions Tab in 2025

4. Use Misleading Subject Lines to Boost Opens

If you use misleading subject lines packed with spammy or promotional words, ESP algorithms will push them straight to spam or the promotions tab.

On the other hand, if you promise something in your subject line and fail to deliver in the email body, your recipients will feel tricked and will likely mark your email as spam.

So to avoid a sticky situation like this, write subject lines that are honest, match the content inside, and set the right expectations for the reader.

5. Send the Same Email to Every Segment Without Tailoring

Sending one generic email to your entire list might be easier, but it ignores the fact that different groups have different needs.

When you skip personalization and segmentation, you risk sending irrelevant content that gets ignored or deleted.

Over time, this leads to lower engagement, more unsubscribes, and worse deliverability.

Segment your audience and tailor your messaging so each group feels like the email was written for them.

6. Not Cleaning Your Email List

Email list hygiene is one of the most underrated parts of bulk emailing.

If you keep sending to inactive or invalid addresses, your bounce rates will shoot up, and ESPs will start treating you as a risky sender.

So make it a habit to:

• Remove hard bounces immediately.
• Segment out inactive subscribers and run a re-engagement campaign.
• Verify new addresses before adding them to your list.

A smaller, cleaner list will always perform better than a huge list full of dead weight.

Note: Even if you use a highly reliable database to source your contacts, you still need to clean your list regularly. People change jobs, email accounts get deactivated, and engagement levels drop over time.

Send Bulk Emails The Right Way!

I hope this blog gave you a clear roadmap for sending bulk emails that actually reach the inbox.

Remember to:

• Set up SPF, DKIM, and DMARC so your domain is trusted.
• Warm up your email accounts before sending at scale.
• Stick to a consistent sending schedule.
• Personalize your emails instead of blasting the same message to everyone.
• Keep your list clean to avoid bounces and spam complaints.
• Stay away from spammy language and misleading subject lines.

When you combine these best practices with a reliable bulk email tool, you’ll improve deliverability, protect your sender reputation, and get better results from every campaign.

FAQs

1. What is bulk email?

Bulk email refers to sending a large number of emails to multiple recipients at once, usually for marketing, promotions, newsletters, or announcements.

2. Is it legal to send bulk emails to cold leads?

Yes, but you must comply with laws like GDPR, CAN-SPAM, or similar regulations in your region. This means you need a clear lawful basis for sending, an opt-out option, and no misleading information.

3. How many bulk emails can I send per day safely?

It depends on your email service provider and account health. Each ESP has its own sending limits. For example, Gmail’s email sending limit is 2,000 emails per day for Google Workspace accounts, whereas free accounts are limited to 500 emails per day.

4. How do I avoid spam filters when sending bulk emails?

Warm up your email accounts, authenticate your domain (SPF, DKIM, DMARC), avoid spammy language, personalize your content, and keep your list clean.

5. Do I need an unsubscribe link in every bulk email?

Yes, for marketing bulk emails, it’s legally required in most countries. Even for cold emails, providing an easy opt-out option helps maintain trust and reduce spam complaints.

6. Can I send bulk emails from Gmail?

No, free Gmail accounts are not made for sending bulk emails. They are more for personal use. However, Google Workspace accounts can support bulk email sending with a higher daily limit of up to 2,000 emails.