Five Reasons Why Your Email Gets Blocked

The question that I typically get asked the most often is, “what are the main reasons that my email gets blocked?” More often than not, the question cannot be answered easily and takes some investigation to uncover the reason or reasons why emails get blocked. Unfortunately, the marketing automation provider or email service provider may not be able to pinpoint the reason either, but reviewing bounce logs will typically help. I have come up with a list of the top five reasons why an email would typically get blocked or blacklisted below:


First off, make sure that the email content you are sending is relevant to your buyer. Everything you send should be centered around the buyer’s needs. A top-of-funnel prospect isn’t interested in your latest promotion, product information, or demo, so why is that what you’re sending? Isolating the buyer by sending content that they’re not ready for will immediately confuse the recipient as to why they signed up for these emails and potentially make them question if they even signed up for these emails at all. If that happens, there’s a chance the recipient reports you as spam, which has a huge impact on your reputation. Make it a priority to produce content that’s relevant and useful, and then test your creative for rendering, HTML errors, link errors (do not use URL shorteners), and mobile design functionality. Don’t forget to do A/B testing on different segments of your list – it matters as it speaks to relevance. For more content tips read: Four Steps To Take Before Launching New Content.


Reputation is a very important factor and includes both IP and domain reputation for the sender. Your sender reputation is built from day one and stays with you for a significant duration (longer than you may like it to). Sending to a large amount of hard bounces, receiving a lot of complaints, hitting spam traps, and getting on a blacklist can all affect your reputation in a negative way. Not to mention getting blocked from particular networks. It’s very hard to turn around a tarnished reputation – do everything you can to keep it in excellent condition, starting by creating content that’s relevant to the buyer.


I often find that marketers will send emails at a high frequency to their recipients. While they make think it’s a solid strategy, running too many marketing campaigns is actually a symptom of tactical demand generation – and it’s costing you a lot more than time and energy. Sending too frequently can often result in recipients blocking messages in their email client, network administrators blocking the sender at the network level, or worse, having your details submitted to a blacklist for sending too frequently. Send wisely and avoid over-communication…at least until you better know your audience and have their permission for frequent communications. If you’re not sure how to break out of this cycle of campaigning, read: The Hidden Costs of Marketing Campaigns.


Sending high volumes to a particular network or domain can often appear like an attack on the mail server. This is especially true for B2B senders who send to smaller business domains. Most often I find that these mail servers will add the sender to their block list because as a result of sending too high of a volume during a particular window of time. For best results, slow down the volumes to these smaller domains to get emails delivered. You don’t have to stop sending, just keep a measured volume and cadence.

Lists – Old & Purchased​:

Both old and purchased lists have a high probability of getting your emails blocked or blacklisted due to the poor quality of the emails that may be on the list. These lists could contain bad email addresses, bad domains, and even spam traps. Many of these people never signed up for the email or weren’t expecting it. This often triggers an email blocked at the local or network level. Always keep data fresh –test it regularly to ensure the people on your list want to be on there and that you’re not violating any privacy regulations. Regular list hygiene is critical and keeping your database current and fully opted-in, or even better, double opt-in is best practice. If you’re sending to a European or California audience, remember to comply with all privacy laws.

The reasons above are just a start to investigating why an email was blocked or blacklisted. The process does take some time to figure out, but uncovering the truth can often get your email delivered and to your intended buyer. Deliverability is the first step to engaging a buyer and driving revenue. If you’re not sure how to take the next step to break out of this cycle of campaigns, read Making the Critical Shift from Tactical Demand Generation to Strategic Demand Marketing.


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