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Cold emailing remains one of the most effective ways to generate leads, book meetings, and initiate business conversations. At LeadCanal, we understand that successful outreach isn’t just about sending more emails.
It’s about sending the right emails safely, strategically, and without damaging your domain reputation.
Sending cold emails incorrectly can result in your emails being marked as spam, a damaged domain reputation, or even having your mailbox blocked.
However, the good news is that by following the proper cold email setup and sending process, you can avoid these issues.
This guide will show you how to send cold emails without getting blocked, protect your domain, and increase your chances of landing in the inbox.
Why Cold Emails Get Blocked
Cold emails often get blocked because email providers detect suspicious sending behaviour. Services like Gmail, Outlook, Yahoo, and others rely on various signals to determine if your email appears trustworthy or if it’s likely to be spam.
Common reasons include:
- Sending too many emails from a new account
- Using an unverified email list
- Getting too many bounces
- Not setting up SPF, DKIM, and DMARC
- Using spammy subject lines
- Adding too many links or attachments
- Sending the same message to hundreds of people
- Getting ignored or marked as spam
To send cold emails safely, your goal is simple: make your sending activity look natural, relevant, and trustworthy.
1. Use a Separate Domain for Cold Email
Never send cold emails from your main business domain. If your main website is company.com, use a separate but related domain such as:
getcompany.comtrycompany.comcompanyhq.com
This protects your main domain reputation. If your cold email domain gets a poor reputation, your regular business emails will not be affected.
For a new domain, avoid sending cold emails immediately. First, set up the domain properly, create professional mailboxes, and give it time to build trust.
2. Set Up SPF, DKIM, and DMARC
Authenticate Your Email Records
Email authentication protocols like SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance)
are essential for ensuring that your emails are recognized as legitimate by receiving servers. These protocols confirm your identity as a trusted sender and prevent your emails from being marked as spoofed.
- SPF: Defines which mail servers are authorized to send emails on behalf of your domain.
- DKIM: Adds a digital signature to your emails, verifying that the email came from the stated sender and has not been altered.
- DMARC: Provides email receivers with instructions on how to handle emails that fail SPF or DKIM checks.
Choose Reputable Providers
While it may be tempting to use free email services like Gmail for cold emailing, using reputable and established email service providers is crucial.
Platforms like Google Workspace, Microsoft 365, or Zoho Mail are far better suited for email marketing and cold emailing, offering better deliverability and security features.
3. Warm Up Your Email Account
A brand-new email account should not start sending 50 cold emails per day. That looks unnatural.
Email warm-up means gradually building sending activity before launching full campaigns. You can do this manually or with a warm-up tool.
The purpose is to create a normal email history with sending receiving and replies.
A simple warm-up plan:
| Time Period | Daily Cold Emails |
|---|---|
| Week 1 | 5–10 emails/day |
| Week 2 | 10–20 emails/day |
| Week 3 | 20–30 emails/day |
| Week 4+ | 30–50 emails/day |
For a new domain, stay conservative Sending slowly is better than getting blocked quickly.
4.Use Email Warm-Up Tools
Before sending bulk cold emails, let your new email account warm up for at least 2-4 weeks. This involves sending small volumes of emails to real, engaged recipients,
gradually increasing the number of emails sent over time.
You can use tools like Warmup Inbox, Instantly.ai, or Mailshake to automate this process these tools simulate organic email exchanges, gradually building your email reputation.
5. Keep Daily Sending Volume Low
One of the biggest mistakes beginners make is sending too many emails too fast.
For cold email, a safe range is usually 25–50 emails per mailbox per day. If your domain reputation is low or your domain is new, start even lower.
Avoid sending:
- 100+ emails from one new mailbox
- Hundreds of emails at the same time
- The same template to everyone
- Large campaigns without testing
If you need to send more emails, use multiple domains and mailboxes but each mailbox should still send at
6: Clean Your Email List
A clean email list is crucial to the success of your cold email campaign. Sending emails to invalid addresses or purchasing third-party email lists can result in high bounce rates and spam complaints.
Verify Email Addresses
Before sending emails, use email verification services like ZeroBounce or NeverBounce to clean your list and remove invalid email addresses. If your bounce rate exceeds 2%, it can severely impact your sender reputation and result in your emails being blocked.
Avoid Spam Traps
Spam traps are email addresses specifically designed to catch spammers. Purchased email lists often contain spam traps, which can negatively affect your reputation and result in your emails being flagged as spam. Always use verified, opt-in leads and avoid purchased or outdated email lists.
7: Optimize Your Sending Behaviour
Your sending behaviour is just as important as your email content. How and when you send emails can have a significant impact on whether or not they end up in the inbox.
Cap Daily Sends
One of the most common mistakes that lead to email blocking is sending too many emails from a single account. Limit the number of emails you send per day to 30-50 emails per inbox.
If you need to send thousands of emails, consider using multiple inboxes to distribute the load. This horizontal scaling helps you avoid looking like a spammer.
Use Random Intervals
Sending emails at regular, predictable intervals makes it easy for spam filters to spot automation. Instead, space out your sends randomly. Tools like Woodpecker, Saleshandy, and Mailshake allow you to automate email sends while ensuring they are spaced out at random intervals (e.g., every 8–15 minutes).
Avoid Tracking Pixels
Tracking pixels are often used to measure the effectiveness of email campaigns, but they can reduce email deliverability. Some spam filters flag emails that contain tracking pixels.
If your deliverability is low, consider disabling these pixels, or use them sparingly.
8: Follow Content Best Practices
The content of your cold email is equally important in ensuring it reaches the inbox. Here are some content best practices that can help you avoid being flagged as spam:
Personalization
Personalization is key to making your emails feel less automated. Use the recipient’s name, company name, or details about their recent work to make the email more relevant.
Tools like Mail Merge or Saleshandy can help you personalize emails at scale.
Avoid Spam Trigger Words
Certain words and phrases are known to trigger spam filters words like “FREE,” “Limited Time Offer,” and “Winner” can increase the likelihood of your email being flagged. Avoid using these words, especially in the subject line, and steer clear of all-caps text.
Keep Formatting Simple
Keep your email formatting clean and simple. Use plain text or basic HTML without large images, excessive links, or flashy designs. Complex formatting can make your email appear spammy and reduce deliverability.
Include an Opt-Out Option
To comply with the CAN-SPAM Act, always include an opt-out or unsubscribe link in your email. This is essential not only for legal compliance but also to avoid complaints and spam reports from recipients.
Monitor and Optimize Your Campaign
Once your campaign is live, it’s essential to monitor its performance and make adjustments as needed.
Track Key Metrics
Use email tracking tools like Saleshandy, Woodpecker, or Mailgun to track open rates, click-through rates, bounce rates, and unsubscribe rates.
these metrics will help you gauge the effectiveness of your cold email campaign and identify areas for improvement.
Analyze Deliverability
If your emails are not landing in the inbox, there may be an issue with your email infrastructure, content, or sending behaviour.
Regularly analyze your deliverability metrics and take corrective actions. Tools like Mailgun or SendGrid can provide insights into your campaign’s performance.
A/B Testing
A/B testing is a great way to optimize your cold emails over time. Test different subject lines, email copy, and calls to action (CTAs) to determine what resonates best with your audience.
Continuously refine your strategy based on the results.
Maintain Consistency and Patience
Sending cold emails is not a one-off task. It requires continuous effort and patience. By maintaining consistent email practices and constantly refining your strategy,
you can build a strong sender reputation and improve your deliverability over time.
Conclusion
Sending cold emails without getting blocked is entirely possible if you follow the right steps. By setting up proper email infrastructure, warming up your account, cleaning your list,
optimizing your sending behavior, and adhering to content best practices, you can significantly improve your chances of success.
It’s important to remember that email deliverability is a long-term process. Therefore, be consistent, monitor your metrics, and continuously optimize your strategy to maintain a positive sender reputation.
As a result, you’ll ensure that your cold emails reach the inbox and achieve the desired results.
