Have you ever failed to send an email using your Yahoo mail and wondered, “Why is Yahoo blocking my emails?”

Yahoo! Mail has nearly 230 million active users worldwide in 2022. However, it is more than just another email provider. It also has spam filters, a virus scanner, and unlimited storage (1TB for Yahoo Standard Mail vs. 15GB mail storage in Gmail).

There’s a catch with Yahoo, though. They could flag your account if they believe you are abusing their platform. And if you’re an email marketer, this is a significant problem. The impact on your business can be devastating, mainly if you rely on email marketing for customer correspondence and lead generation.

But here’s the good news: you can remedy the situation or prevent it from happening. That’s what we will share with you today: the common reasons Yahoo blocks your emails and what you can do about it.

Before we dive in, let’s first find out how to tell if Yahoo blocked you:

How to Tell if Yahoo Blocked You

Finger pointing

If you are unfamiliar with the Yahoo Mail Postmaster Tool or already using deliverability tools like InboxAlly, let’s start here.

Using Yahoo’s tools to check your deliverability is a significant first step to seeing what deliverability looks like from their perspective. It is also a must-have tool to use as part of your regular workflow to monitor deliverability issues.

What is the Yahoo Mail Postmaster Tool?

Yahoo Mail Postmaster Tool is a specialized tool from Yahoo. You can utilize it to analyze and monitor your email health and find suitable routes for your messages to reach the inbox. You can also set up a Feedback Loop with it, and once you have, you can receive spam rate reports.

How to Perform a Yahoo Blacklist Check

Unlike anti-spam DNS blacklist services like Spamcop and Spamhaus, you cannot search an IP at Yahoo to determine if they blacklisted your email. Typically, you will know if they rejected your email if you receive a message like this:

553 5.7.1 [BL21] Connections will not be accepted from,

because the ip is in Spamhaus’s list; see <a href=”http://postmaster.yahoo.com/550-bl23.html”>http://postmaster.yahoo.com/550-bl23.html</a>”

Another variation is:

“421 4.7.0 [TS01] Messages from <> temporarily deferred due to user complaints

<> ;see http://postmaster.yahoo.com/421-ts01.html”

You can also check other Yahoo’s SMTP Error Codes to find the specific codes in the email bounce when your emails are not delivered.

However, if you think the intricacies of email coding are beyond your expectations, just look for specific error codes, like “TS01” or “BL21.” These error codes and a link often tell you the SMTP error and why the emails you sent to Yahoo are returning.

Now, let’s answer your question, “Why is Yahoo blocking my emails and what to do about it?”

9 Reasons Why Yahoo Blocks Your Emails

1. Unauthenticated Email

One of the common reasons why Yahoo blocks your emails is that you are using an unauthenticated email.

Remember that verifying your domain or authenticating your reputation with the Internet Service Providers (ISPs) is essential to increase your chance of delivering your campaigns to the inbox.

For Yahoo email IDs, you can use these three authentication protocols: Sender Policy Framework (SPF), Domain keys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting & Conformance (DMARC).

An inbound email server will also use different methods depending on how it is configured. This will determine whether an email comes from the server authorized to send on behalf of such an email address, the email address it claims it is from, and the server it claims it is from. The “from” address is a crucial component of this.

Read also: SPF, DKIM, and DMARC Explained – Infographic

2. Spammy-Looking Content

Another reason Yahoo filters your email is that they look spammy. Spam emails often have these in common: subject lines written in ALL CAPS, often in bold font size, unknown email addresses in the From field, and pure sales and promotional content.

Moreover, Yahoo also blocks some emails because they contain too many links. Remember that it is common for corporate networks and ISPs to create their custom criteria for blocking. This also includes a trigger of spam filters when an email is loaded with hyperlinks.

Many ISPs use information from content filters and blacklists in a weighted system, creating spam points for each offensive message.

Here are things that spam filters can catch:

  • Frequent or random capitalization
  • Poor spelling in the email subject line or content
  • Regular variations in text size and color
  • Scam-like subject lines
  • An entire email composed of capital letters
  • Excessive punctuation, especially “!” and “$.”

Therefore, when an incoming email reaches a spam point above the threshold, Yahoo will tag the email as spam and go straight to the spam folder. If not, it may bounce back to you, the sender.

But I have never sent spam messages, or my content doesn’t even look spammy.

In this case, you could focus on technical sending issues. This leads us to another reason why Yahoo blocks your emails.

3. Email Deliverability Issues

You will likely have deliverability problems if your emails bounce or land in the spam folder. This is quite a common challenge that other marketers face while implementing their email marketing strategies.

Deliverability problems can also happen when the customer’s inbox is full, or the email address they provided is incorrect. If you have a low deliverability score, you could also lose face with the internet service provider, and your email marketing efforts are null.

However, you can solve this by maintaining your list regularly or providing links for your recipients to use when registering their new emails should they change emails. You can also send email confirmation links to prospective or existing customers to improve your rate of getting genuine and existing emails.

4. Poor Data Integration

Data is the internet’s version of precious stones. Without it, businesses would more or less be lost because data provides a direction that companies would follow.

No wonder why marketers go a little bit crazy when they’re collecting email data. They simply want enough material to create sensational marketing messages that resonate with prospective and existing customers.

Additionally, the problem occurs when they gather too much data, and a company or a marketer must integrate them with other data systems. The good thing is that you can wriggle out of it by not being too greedy.

Therefore, gather as much data as you can confidently integrate with your other data systems and then build on it. That way, you can ensure efficient data integration. You can also use data integration services and tools to give you what you need in the data collection process.

These tools would help you gather the data from several designated hotspots. You can also use an online service that declutters email data by removing the bad data, preventing invalid and blocked addresses from taking up space in email, and keeping your data fresh.

5. Sudden Change in Email Volume

Man looking at his laptop

If your sending volume needs to be corrected or consistent, you may encounter delivery issues when sending to a Yahoo account. Every time your volume increases dramatically, mailbox providers can treat your email as spam.

Therefore, you need a warm-up process to increase your email-sending volume gradually. You can also try the email sunset policy, which is jargon for data pruning practice, where you remove inactive lists if they are not responding to your campaigns after a certain period.

When you’re ready to dive deep into email marketing, How to Send Mass Emails Without Landing in Spam is a great resource.

6. ISP Block Bounce

We mentioned earlier that ISPs use spam-blocking measures to sort incoming emails and determine if an email should be considered spam.

Sometimes, however, said measures can inadvertently block even legitimate emails because the ISP cannot be entirely sure if the message was legitimately requested in the first place.

We call it an ISP Block bounce, meaning the message was not delivered to the recipient as the receiving mail provider rejected it. An ISP block also happens most commonly due to a local policy by the receiving mail server.

However, in rare cases, ISP blocks can also occur because of a reputation issue with the IP addresses used when sending the message.

7. Email Domain Not Marked as a Safe Sender

Email filters now focus more strongly on commercial emails or “graymail.” This is another reason why the intended recipients do not receive legitimate emails. The same spam filters automatically recognize blacklisted and whitelisted email addresses.

So, when an email domain is not marked as a safe sender, they are not automatically deemed acceptable and will still have to undergo additional filtering. Moreover, Yahoo offers a blocking option for users to block email addresses from which they get the most spam emails.

That’s why it’d be best to get your email domain marked as a safe sender. Doing so helps your newsletters or emails get straight into the inbox of your recipients, with no more swords of spam email hanging over your head.

You can ask your engaged and loyal customer list to mark your emails as safe senders. Often, they can select the Settings gear icon in Yahoo. There, they can find the Filter and Blocked sender list.

8. Repeatedly Sending to Invalid Email Addresses

If you repeatedly send invalid emails to Yahoo or blocked email addresses, it could be another reason your emails are blocked.

So, build your email list using an opt-in with an email validation process and ensure your list hygiene. This is also a great way to avoid sending emails or newsletters to invalid addresses.

9. Spamming Complaints

You may have an efficient email marketing contact list, but it won’t mean much if you overload your recipients with too much email.

If your recipients get too many emails from you, it could cause them to unsubscribe from your mailing list, regardless of how much they resonate with your content.

You can quickly solve this by making it easier for your recipients to choose. So, clear your options from the beginning, and be ready to readjust your marketing plans occasionally.

Read also: The Most Important Email Marketing Statistics in 2022

Email Delivery Tips for Marketing to Yahoo Users: Steps on How to Stop Yahoo from Blocking Your Emails

For all the email marketers out there who face the problem of Yahoo rejecting your emails, we’re here to help. Below are some tips to stop Yahoo from blocking your emails:

Create an email marketing plan

A successful email marketing campaign begins with a strategy. For instance, know the context of your campaign, define your goals and objectives, consider signup sources, decide what to write, and establish your sending frequency.

Some of the best practices for sending to a Yahoo Mail account

  • Make a schedule or create a calendar to create content
  • Create groups and segments
  • Get to know your audience

Keep your email design straightforward

Now that you’ve created an email marketing plan, the next step is to consider the design of your emails. At best, focus on the message when designing your email campaigns and keep your design straightforward.

We also suggest laying out all the elements of your email campaign in a hierarchy, such that you put the main takeaway or most important information at the top so readers can quickly scan your email if they are short on time. You can also code your templates to have more control over your email design.

Test in different ISPs and email clients

The next step is to test your emails with different ISPs and clients. All email clients are not created the same way, meaning the campaign you design may look slightly different when delivered to your subscribers’ inboxes.

You can check your emails on different devices first. Remember that there might be a problem with your internet connection. So, try running a speed test to ensure your emails land in the inbox, not the spam folder.

By running a test, you may also know if you have a compromised user account that has been used to send spam.

If you have coworkers or friends who can check your email for typos and will give you feedback on the layout, send them your test email so they can preview your campaign directly from their inbox.

However, if you’re unsure which subject line to use to get the most opens and clicks, you can run an A/B test. By testing your campaigns, you experiment with different versions of your emails and see how changes can impact your results.

Utilize email marketing automation

If you have been following this topic from the start, you may have already learned how to keep your emails highly relevant to each subscriber and send effective emails with a high open rate. Now, be ready to automate the process and turn your email marketing campaign into a money-making machine!

Automating your campaign is one of the most powerful tools for making sales. It helps email marketers engage their email list, turn prospects into buyers, and build relationships. And the best part is that the moment you build it, your work is done. You can then focus more on the crucial aspects of your business.

Using an autoresponder or automating emails nurtures leads and turns prospects into customers.

Measure your performance

Congratulations on making it to the fifth and final section of this guide. You have come a long way.

The last step is to measure your performance. This step allows you to refine your email marketing strategy going forward. Some of the most important statistics for measuring the success of your campaign include opens and clicks, e-commerce data, and website traffic.

However, it is also essential to consider how your open and click-through rates compare to other businesses in your industry. Otherwise, you look at your email marketing statistics in a vacuum.

Email Like a Pro

Man shocked in front of his laptop - why is yahoo blocking my emails

Getting your email into the inbox is a top priority. Hopefully, some of these tips will be a go-to thing for your email marketing campaign.

And if none of the solutions work for your emails, don’t hesitate to contact Yahoo. A representative may walk you through additional troubleshooting steps so you can finally hit your Yahoo customers’ inboxes every time.

Till then, happy emailing!

Want to see how InboxAlly can help your business master email deliverability? Contact us today.


[1] https://financesonline.com/number-of-email-users/#:~:text=This%20is%20followed%20by%20Outlook,nearly%20230%20million%20active%20users.