How Email Marketer Becomes a Trusted Sender

A trusted sender is someone who has explicit permission from recipients to send them emails.
When a sender is marked as safe or trusted, their emails consistently reach the inbox. So how exactly does one build email trust? Is the only way to ask recipients to whitelist your email? Will all your emails go to spam if you don’t do so? How can you navigate being flagged as an email spam sender?
Worry not! We will break down the concept of safe senders for both email users and email marketers. We also explain what is a safe senders list and how both parties can benefit from it.
But before we do that, let’s understand the main reason why trusted senders exist: spam.
How Serious is the Spam Problem in 2025?
Email spam is defined as unsolicited, bulk electronic messages users receive unwillingly. They’re generally considered a nuisance and can even be dangerous. While they have reduced in volume, they still remain a significant threat even today.
These spam highlights convey the seriousness of the matter:
- According to Statista, spam accounted for around 46.8% of all emails in December 2023. This is a staggering amount of unwanted and potentially malicious emails.
- Spam costs businesses and organizations billions of dollars annually in lost productivity, infrastructure costs, and efforts to combat it.
- Spam clogs inboxes, wastes time, and creates frustration for email users. This diminishes the effectiveness and usability of email as a communication tool.
- Many spam emails are used for phishing attacks, distributing malware, or other cybercrime activities, putting users’ data and systems at risk.
Next, let’s review what’s being done about all this spam.
How is the Email Industry Fighting Spam?
Combating spam is an ongoing battle requiring collaboration between email service providers (ESPs), security agencies, the authorities, and users themselves.
Effective spam prevention measures can help tackle these problems and create a more secure email ecosystem.
To combat this persistent problem, various efforts have been undertaken:
Measures | How they reduce spam |
---|---|
Spam filters | The use of techniques like content analysis, sender reputation scoring, machine learning, and real-time blacklists to block spam. |
Email security protocols | Protocols such as SPF, DKIM, DMARC, and BIMI help identify legitimate email senders and reduce spoofing attempts. |
CAN-SPAM and GDPR | Countries have enacted laws and regulations — such as CAN-SPAM and GDPR — allowing for legal action against spammers. |
Private email servers | Companies use solutions like anti-spam, anti-phishing, and anti-malware components to protect their email systems. |
We all agree spam is a grave issue; here’s where safe senders come in.
What is a Trusted Sender?
A trusted sender or safe sender is an individual with a specific email address who has been explicitly marked as safe by the email recipient or mailbox provider.
There are two main contexts where you might hear this term:
- Email marketing,
- Personal email.
What is a Trusted Sender in Email Marketing?
Mailbox providers use the sending history of an email address or domain to classify it as a trusted sender.
In email marketing, a trusted sender is an entity adhering to good practices. Bad email marketing practices will lead to you being marked as an untrusted sender.
Senders build email marketing trust when they:
- Only send emails to recipients who have opted in to receive them.
- Avoid behaving like a spam email sender; don’t use misleading email subject lines or send excessive emails.
- Maintain a good email sender reputation by following best practices.
Mails sent by a safe sender are typically not marked as spam or blocked by spam filters. This is a desirable trait for email marketers who regularly dispatch emails. Being trusted means their emails won’t be caught by spam filters due to their content or volume.
Mailbox providers view senders as trusted under these conditions:
Method | The sender is seen as trusted when: |
---|---|
Whitelisting | When recipients explicitly mark the sender as safe. |
Safe senders list | The email address is on a centralized “Safe Senders List” which includes popular and reputable senders. |
Authentication | Authentication protocols like SPF, DKIM, DMARC, and BIMI are properly implemented. |
Feedback loop | When recipients mark emails as “not spam,” the provider’s spam filters learn and trust that sender. |
Being designated as a safe sender ensures better email deliverability, as messages from such senders are less likely to end up in spam folders. That said, messages with malware and phishing emails get quarantined regardless of safe sender settings.
What is a Trusted Sender in Email?
Email users get the final say on whether an email sender is trusted or not. Recipients have to manually mark someone as a trusted sender to receive their emails without issues.
Email clients such as Microsoft Outlook or Gmail allow users to create a safe senders list or a “whitelist.”
What is a Safe Sender List?
A safe sender list is a list of email addresses or email domains they can designate as safe. Emails from these senders will bypass the spam filter and reach the inbox.
In the early days of spam, clunky security measures were causing more harm than good. The concept of an email safe sender list arose as a solution to these issues.
If you’ve ever wondered how to mark a sender as safe in Gmail so you get their emails without problems, the safe sender list is the answer.
Why Were Safe Sender Lists Created?
The trusted senders list was created because:
- Early spam filters relied heavily on content analysis and simple rules, which misidentified legitimate emails as spam. This was doubly true for emails containing certain keywords or using common spammer formats.
- False positives caused individuals and businesses to miss out on opportunities, as important emails from colleagues or clients were incorrectly blocked.
- There was a growing demand from email users for a way to mark certain email addresses or domains as safe.
- Spam filters were wonky at the beginning; these systems could sometimes penalize legitimate senders or incorrectly associate them with spammers. Some senders even had poor reputations due to factors beyond their control.
- The safe senders feature allowed organizations to control and customize their spam filtering experience. They could then tailor it based on their specific needs and open up trusted email channels.
And thus, being able to add email to safe sender list became a common feature of all email clients and services.
How Do I Add an Email Address to My Safe Senders List?
Marking a contact as trusted is pretty simple. Doing so prevents missing time-sensitive information or critical updates from important senders.
This section shares instructions on how to add senders to the Safe Senders list, giving email users complete control over who can reach their inboxes.
Let’s begin with how to add email as trusted in Gmail.
How to Add Trusted Senders in Gmail?




The steps show you how to add a trusted email address to Gmail.
Adding a trusted or safe sender on Gmail is simple:
- Open Gmail and click on the Settings gear icon.
- Select “See all settings”.
- Go to the “Filters and Blocked Addresses” tab and then click on “Create a new filter”.
- Enter the email address or domain to whitelist in the “From” field.
- Click “Create filter”.
- Check the box next to “Mark it as important”.
- Click “Create filter” again to save the changes.
Once added to the list, emails from a Gmail-safe sender will no longer go to spam.
How to Add a Trusted Sender in Gmail App
Both iOS and Android apps allow you to add safe senders in Gmail.
You can go to the spam folder on Gmail and mark an email as important by clicking the three-dot menu in the top-right corner.

You now know how to add trusted sender in Gmail. Once you follow the Gmail add trusted sender process, all emails from the address will be delivered to the primary Gmail inbox.
Next, we cover how to mark a sender as safe in Outlook.
How to Mark Someone as Safe Sender in Outlook?



Adding a contact to the safe sender Outlook list is straightforward:
- Log in to web Outlook on a browser.
- In the top right corner, click the gear icon to open settings.
- Click on the “Junk email” tab.
- In the “Safe senders and domains” section, click on the “Add” button.
- Type in the email address or domain you wish to add as a safe sender.
- Press Enter on your keyboard.
- Click on the “Save” button at the bottom.
All future emails from the Outlook safe sender will now appear in the main inbox. The Outlook add trusted sender method is the best way to ensure error-free email delivery.
How to Be a Hotmail Trusted Sender
Hotmail does not exist anymore; it is now Outlook.com. You can sign in to Outlook with your Hotmail credentials.
Once you log in, follow the steps we’ve shared above to add to or edit your safe senders list. Then, like Gmail safe senders, Hotmail trusted senders can send emails without going to spam or getting blocked.
How to Add Email to Safe Sender List Apple Mail



If an email sender is already on the Contacts list, they will not be marked as spam. So the easiest way to ensure someone is a safe sender is to add their email to the list of contacts on Apple Mail.
Here’s the second method:
- Open Apple Mail on your Mac and go to Mail > Settings.
- In the new popup window, click on the “Rules” tab.
- Click on the “Add Rule” button.
- Set the first drop-down list to “From” and the second to “ends with.”
- Enter the email address/domain you want to mark as trusted in the text field.
- In the next section, choose “Move Message” in the first drop-down list and “Inbox” in the second.
- Click “OK” to save the rule.
That’s it! The Mail app will now view all emails from the particular sender as trusted.
How to Add an Email as a Trusted Sender on My Company Email Account?
We’ve already shared steps for popular email services and clients above. For company email accounts, the process varies slightly depending on your company’s email system.
To add an email as a trusted sender, typically you’ll need to access your email client’s settings related to spam or junk mail filtering. Look for options like “Safe Senders,” “Whitelist,” or “Allowed Senders.” Within these safe sender settings, you should find a way to add specific email addresses or domains. If you can’t simply reach out to your IT admin or tech team.
Entering the desired email address or domain and saving the changes will usually mark that sender as trusted, ensuring messages bypass the spam filter.
Trusted Email Domains
Adding a trusted email domain allows all emails from that domain — say, “@campaignrefinery.com” — to bypass the spam filter.
This can be incredibly beneficial when dealing with organizations using multiple email addresses. It’s also suitable for when you expect emails from various individuals within a company. Instead of adding each address, you can simply add the domain once, saving time and effort.
Trusted domains are added the same way as individual email addresses.
It’s crucial to exercise caution when adding domains, especially public domains such as @gmail.com or @yahoo.com. These domains are used by millions of individuals, including spammers and malicious actors.
What are the Advantages of Being a Trusted Sender?
We can think of numerous scenarios where marking a sender as safe or trusted can be beneficial.
- Emails from safe senders are more likely to bypass spam filters and reach the inbox. This reduces the likelihood of missing important emails due to them being incorrectly marked as spam.
- Some email systems prioritize messages from trusted senders, ensuring their messages are among the first seen.
- With important emails correctly sorted into the inbox, users can organize their emails more efficiently, applying email triage.
- When a recipient marks an email sender as trusted, they’re confirming they recognize and verify the sender. This makes it less likely for them to fall prey to phishing and email spoofing.
- Some email systems provide notifications if an email from a safe sender fails other security checks (such as SPF or DKIM), which can be a sign of malicious activities.
- There’s less need to regularly check the spam or junk mail folder for missed emails.
- The incidence of false positives (legitimate emails marked as spam) decreases with accurate safe sender lists.
- Marking colleagues or vendors as trusted senders ensures the flow of email chains remains uninterrupted. This is crucial for timely decisions and operations.
- Knowing an email comes from a trusted source can increase confidence when opening and interacting with the content.
When marking someone as a safe sender, it’s crucial to ensure the email address is verified. Always confirm the ID is legitimately associated with the corresponding individual/business.
Deliverability Challenges Faced by Email Marketers
Now that we’ve explained the “trusted sender” topic in the context of email users, how about email marketing?
Every email professional wants to be considered a safe sender and see their emails land in the inbox. But that’s easier said than done.
The top 8 reasons mailbox providers view email senders as suspicious are:
- Spam filters: If spam filters detect issues with email content or sending history, the messages will be marked as spam.
- Poor sender reputation: The result of high email bounce rates, spam complaints, or sending practices, a low sender score can lead to emails being blocked.
- Authentication: Improper email authentication can make a sender look suspicious. SPF, DKIM, DMARC, and BIMI are essential to improve email deliverability.
- Poor email list: The quality of your mailing list can significantly impact deliverability. If you have invalid email addresses or buy email lists from untrusted sources, it will result in high bounce rates and spam complaints.
- Spammy content: ISPs look for certain keywords, excessive links, or formatting resembling common spam tactics.
- Low engagement: ISPs evaluate email engagement (or lack of it) to determine deliverability.
- Email volume: Sending too many emails in a short period or exceeding the recommended email volume can raise red flags with mailbox providers.
- Compliance: Non-compliance with regulations can result in deliverability issues and even legal consequences.
If struggle with deliverability, it’s because ESPs think of you as an untrusted sender. Asking every single subscriber to add you to their safe sender list can be a near-impossible task. This is why you must look at more practical ways of achieving better deliverability.
The first and best step marketers can take toward becoming a trusted sender is to work on their sender reputation.
Fixing Your Sender Reputation
If poor sender reputation is an issue you’re facing currently, you should know it’s fixable.
Following these ten points diligently can help you turn the situation around:
- Analyze your email metrics: Review your email campaign metrics, including bounce rates, spam complaints, and email unsubscribe rates, to identify areas needing improvement.
- Clean your email list: Remove invalid, inactive, or outdated email addresses from your mailing list. Use email verification tools to ensure your list is up-to-date and accurate.
- Use a reputable ESP: Consider using a reputable ESP with robust email deliverability tools and expertise.
- Implement authentication protocols: Set up email authentication protocols such as SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), DMARC (Domain-based Message Authentication, Reporting & Conformance), and BIMI (Brand Indicators for Message Identification) to validate your email server’s identity.
- Monitor sending volumes and frequency: Avoid sending too many emails in a short period, as this can trigger spam filters.
- Optimize email content: Ensure your email content is relevant, valuable, and doesn’t resemble spam.
- Encourage engagement: Include attractive email CTAs and make it easy for recipients to engage with your emails. High email engagement metrics can positively impact your sender reputation.
- Provide an easy unsubscribe option: Include a prominent and functional one-click unsubscribe in your emails, so recipients can easily opt out.
- Monitor feedback loops: Participate in feedback loops to receive and process spam complaints appropriately.
- Be patient and consistent: Rebuilding a damaged sender reputation takes time and consistent adherence to best practices. Monitor your metrics and adjust your strategies as needed.
How to Become a Gmail Trusted Sender?
Emails from Gmail trusted senders reach the inbox without any restrictions.
Follow these key strategies to get on the trusted senders Gmail list:
- Implement Feedback Loops (FBLs): Sign up for Gmail’s FBL to identify and remove spam complainers, improving your reputation.
- Use Google Postmaster Tools: Monitor key metrics like spam rate, IP and domain reputation, authentication, and encryption.
- Validate Emails at Signup: Use syntax, domain, MX record checks, and real-time APIs to prevent bad addresses from entering your list.
Next, we show you how to trust a sender in Outlook.
How to Be an Outlook Trusted Sender?
Adding a sender to the trusted senders Outlook list ensures their emails reach the inbox without hiccups.
These 4 guidelines will help you become a trusted sender Outlook approves of:
- Prioritize Outlook-Specific Engagement: Encourage adding to contacts, “Not Junk” clicks, replies, and forwards.
- Leverage SNDS: For large senders, monitor IP reputation via Microsoft’s Smart Network Data Services.
- Optimize Email Formatting: Avoid complex HTML and test rendering in various Outlook clients.
- Consider Microsoft Deliverability Support (For Enterprise): Contact their support team for advanced troubleshooting.
Partnering with trusted email providers is a critical step in consistent inbox placement; that’s why this next section is relevant for you.
Campaign Refinery: Always Be a Trusted Sender
As the number one email deliverability platform in the industry, Campaign Refinery is home to only safe senders. We enjoy an excellent reputation with mailbox providers because we put in the hard work to get here!
These are the tools and methods we use for top-tier inbox placement:
- Approval system for new clients: New accounts have to go through an approval process, which helps prevent the onboarding of spammers.
- Mandate on authentication protocols: We require all clients to implement SPF, DKIM, and DMARC before they can begin sending different types of email campaigns. We are already BIMI-certified ourselves!
- Powerful segmentation and tagging tools: Master email list management to ensure the best engagement rates. Your subscribers and mailbox providers will love you!
- Robust analytics: If there are trends, upwards or downwards, our customers will immediately know, thanks to our accurate and visual analytics dashboard.
- Automated list cleaner: Our list cleaning tool removes spam traps, complainers, role-based emails, and seeder and burner accounts.
- Valid email lists: We require our clients to maintain a valid email address list.
- Ban on buying lists: Cold emailing is prohibited at Campaign Refinery as are purchased lists.
- Server monitoring: We constantly monitor client metrics to ensure no spam is sent from our servers.
- Acceptable use policy: We monitor accounts consistently performing poorly, and low engagement stats like open rates below 10% or bounce rates over 10% lead to account suspension.
Apply to be a Campaign Refinery customer — become a trusted sender today!
FAQ
What Does “some content in this message has been blocked because the sender isn’t in your safe senders list” Mean?
This message means your email client has blocked certain elements of the email (like images or external links) because it doesn’t recognize the sender as someone you’ve explicitly trusted. This is a security measure to protect you from potentially harmful content in emails from unknown sources.
How to Mark Sender as Important Gmail?
To mark a sender as important in Gmail, learn how to make someone a safe sender in Gmail. This will prioritize emails from a safe sender Gmail approves of.
Which Email Feature Allows You to Mark Certain Sender as Safe?
The email feature allowing you to mark certain senders as safe is typically called “Safe Senders” or “Trusted Senders.” If you want emails from a safe sender in Gmail to be delivered without errors or failures, you must learn how to mark emails as safe in Gmail.
How to Mark a Sender as Important in Gmail?
To mark a sender as important in Gmail, you can either add them to your Contacts, prioritizing their emails. You can also manually mark individual emails by clicking the “Mark as important” icon. This adds them to your trusted senders list Gmail.
Is It True Phishing Emails Are Fake Emails That Appear to Come From a Trusted Sender?
Yes, phishing emails are indeed fake emails designed to look like they come from a legitimate or trusted sender. They pretend to be from a bank, social media site, or colleague to trick you into revealing personal information.
Does Gmail Have a Safe Senders List?
While Gmail doesn’t have a feature explicitly named “Safe Senders List,” it offers similar functionality through filters and contacts. You can create filters to ensure emails from specific senders are never sent to spam.
What is a Sender?
In the context of email, a sender is the person or entity sending an email message. It is identified by the “From” address in the email header. This address is what recipients see as the source of the email.
How to Add a Trusted Sender in Gmail?
You can add trusted email to Gmail by adding them to your Contacts, which prioritizes their emails. You can also create a filter preventing their messages from being sent to spam.