Cold Outreach Best Practices for Outlook: 2025 Guide

Cold email outreach has become an indispensable strategy in 2025 for building connections, generating leads, and acquiring new clients. However, as email filters and spam detection systems evolve, the success of your cold outreach relies heavily on compliance with best practices - especially when using Outlook. This guide will provide valuable strategies to not only avoid deliverability problems but also ensure you maintain a strong sender reputation while sending bulk emails in Outlook.

Cold Outreach Best Practices for Domain and Mailbox

Set up DNS records

Proper email authentication is crucial to help Outlook recognize your domain as a legitimate and trusted sender.

Understanding Email Authentication in Simple Terms:

1️⃣ SPF Record – It helps prevent email spoofing by specifying which mail servers are authorized to send emails on behalf of your domain.

2️⃣ DKIM Record - It adds a digital signature to your emails, allowing recipients to verify their authenticity.

3️⃣ DMARC Policy – It protects your domain by ensuring that unauthorized entities cannot use it to send fraudulent emails.

How can you check if your domain's authentication setup is correct?

• We suggest using Inbox Insights, a free tool that tests your email deliverability. By sending emails to seed accounts, you will receive a detailed report on your email performance and deliverability.

Where can you generate the required DNS records for your domain?

• For ease and speed, we use SPF and DMARC generators. These quick and efficient tools deliver the results directly to your inbox within minutes.

Use humanized mailbox names

When you send mass emails in Outlook, it's especially important to use a humanized mailbox name instead of a generic one. This signals to Outlook that you are a real sender, helping build trust and reducing the likelihood of being flagged as spam.

Generic mailbox names: sales@chargemyemail.com, support@chargemyemail.com.

Recommended mailbox name: alex@chargemyemail.com, stephen@chargemyemail.com.

Increase sending limits slowly

Remember the wisdom of taking small steps while you achieve your goal.

The same principle applies when it comes to increasing your sending limits.

You can’t expect to send 300 emails daily from a newly created inbox. If you’re too aggressive with your outreach and send too many emails too quickly, your emails will land in the junk folder. This is particularly true if your domain doesn’t yet have a solid reputation.

Before diving into large-scale campaigns, you must convince Outlook that you are a trusted sender and that your emails are worth approving. Building that reputation takes time.

Start by preparing your domain. Here’s what we recommend:

8-12 weeks warmup process:

• Begin with sending between 20 and 30 emails per day.
• Increase the number of emails by 10-20 per day, provided your spam rate remains stable.
• After your domain is sufficiently warmed up, you can comfortably send up to 200-300 emails daily.

Typically, it takes 2-3 months to establish a good sending reputation. Patience is key if you want to send bulk emails in Outlook, land in the Inbox folder, and receive a lot of replies.

Send no more than 200 emails from one mailbox

We strongly recommend not sending more than 200 cold emails from a single mailbox, even if Outlook allows for higher limits.

So, what should you do if your KPIs require sending 600 emails daily? A solution could be setting up two additional mailboxes, allowing you to send 200 emails from each, meeting your KPI while keeping your account safe and compliant with best practices for sending mass emails in Outlook.

Ensure there is a right delay between cold emails

It’s essential to show to Outlook that you are a genuine person sending meaningful emails, not a spammer or bot.

The ideal delay we recommend to our clients (and use at Charge) is 180 seconds or 3 minutes.

This means that when launching your email outreach campaign, you should either set an automated delay of 180 seconds between each email or follow this delay if you're doing it manually.

This delay avoids triggering spam filters and ensures you can send bulk emails in Outlook without causing any issues with deliverability.

Use a separate domain for cold outreach

Using your main domain for cold outreach can negatively affect its reputation due to low engagement rates, leading to a diminished sender reputation.

Here are two possible approaches to organizing your outreach infrastructure:

Not recommended option: Using your main domain or subdomain for both cold and warm outreach.

Best option we recommend: Creating a dedicated domain for your cold outreach.

Additionally, based on our experience, we suggest purchasing a few backup domains if your budget allows. This ensures you’re prepared for unexpected issues with your main domain, enabling you to continue your outreach without long pauses.

Cold Outreach Best Practices for Recipient Database

A well-maintained, up-to-date prospect list is vital for ensuring high email deliverability. You need to be confident that your emails are relevant to the recipients and that their contact information is accurate to avoid high bounce rates.

Let’s review some tips that go beyond the basics:

Don’t trust websites selling leads

We cannot emphasize enough how risky it is to trust websites that sell leads. Buying email lists is not only non-compliant with email laws but is also highly ineffective. In most cases, these lists contain outdated or irrelevant information. Targeting the wrong audience leads to low engagement rates, which harms your inbox deliverability and sender reputation.

That being said, we understand there may be times when you might consider using such services. If you have to purchase contacts, proceed with extreme caution. In many cases, the leads you buy will have bad quality.

We highly recommend verifying purchased email lists through tools like ZeroBounce or, for a more sustainable approach, manually testing the contacts by sending test emails from another account that has nothing related to your main domain.

Avoid reaching more than three individuals within the same domain

It’s generally a good practice to avoid targeting too many people within a single domain. Instead, we recommend focusing on a few key individuals - typically 2-3 - within a given company.

By following this strategy, you can maintain a positive sender reputation and significantly reduce the probability of your emails being marked as spam. A lot of companies have spam protection tools that will reject emails from a single sender if they receive too many in a short period.

Send cold emails only to business accounts, preferably to the same ESP

When sending emails from one Outlook address to another Outlook address, email delivery is generally smoother, because Outlook prefer emails from their own servers. It minimizes issues with SPF, DKIM, and DMARC authentication, which can cause emails from different ESPs to be rejected or marked as suspicious.

However, it’s important to focus your cold outreach on business accounts rather than free mailboxes. This helps improve deliverability and reduces the chances of your cold emails being marked as spam. By using paid business email accounts, you’ll improve your chances of getting positive responses and avoid deliverability issues when you send mass emails in Outlook.

Cold Outreach Best Practices for for Content

Now, let’s cover how to maximize the chances that your emails will not only reach your recipients but also get opened - despite the sheer volume of other emails they may be receiving.

Although we can’t guarantee a 100% open rate, implementing the following strategies will significantly boost your chances.

Use a free spam words checker

Certain words in your email content can trigger spam filters, but manually checking every email for these terms can be tedious. That’s why we recommend using a free online spam word checker, created by Folderly.

Do not use attachments, media, or links

When conducting cold outreach, we recommend not using attachments, visuals, or links in your emails. Since you're contacting domains for the first time, sending such media or links/attachments can make your outreach look suspicious and unprofessional.

Keep emails under 1000 characters

In cold outreach, less is more.

We recommend keeping your emails short - ideally under 1000 characters. Short emails are more likely to capture recipient’s attention and are less likely to be flagged as spam, especially when you send emails to a new audience.

Test email deliverability with the same templates you plan to use for outreach (including signature)

It’s essential to test email deliverability using the exact templates you plan to send. Many people ignore the importance of including their signature when testing email templates. Since email signatures can also trigger spam filters, make sure to test with your full email.

Update your email templates and sequences every 2 weeks

It’s important to regularly update your email templates and sequences to stay ahead of spam filters. As spam detection algorithms improve, what worked previously might no longer be effective.

By refreshing your content every two weeks, you can adapt to changes and improve the likelihood that your emails will reach their recipients, rather than getting lost in spam.

Use straightforward subject lines

Using misleading subject lines like "Your business is in danger" is an outdated tactic that is no longer effective. Outlook encourages clear subject lines that accurately represent the email content. A well-crafted subject line will grab attention and set clear expectations for the recipient.

Although catchy subject lines can spark curiosity, misleading ones will likely frustrate your recipients. Instead, focus on crafting subject lines that build trust and provide a clear reason for your email.

Send emails in one primary language from each domain

Stick to one language for each domain. This simplifies things for recipients and reduces the chances of being flagged as spam. It also enables you to personalize your message, which builds trust with potential clients.

If you're targeting a global audience, consider segmenting your emails based on language preferences, which shows extra effort and improves the likelihood of your message being understood.

FAQs

1. How can I send bulk emails in Outlook without hitting the junk folder?

Warm up your domain gradually, stick to the 200 email daily limit, and always use verified contact lists. Avoid using spammy words, attachments, or excessive links.

2. Can I use my main domain for cold email outreach?

It’s not recommended. To protect your main domain's reputation, it's safer to use a separate domain for cold outreach.

3. What’s the best way to check if my cold emails are spammy?

Use a spam words checker like Folderly’s Spam Words Checker and test your emails deliverability before sending them to real people.

4. How often should I update my email templates?

It’s a good practice to refresh your templates every 2 weeks to stay ahead of spam filters to improve email performance.

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