Summary
Despite a qualified subscriber base and good practices being followed, your emails end up in spam. Upon further investigation, you discover that your IP is blacklisted. One of the possible causes: snowshoe spamming.
This technique, exploited by spammers, consists of dispersing mailings across several IPs and domains to circumvent anti-spam filters. Unfortunately, some legitimate senders may be penalized unintentionally. Understanding the phenomenon and knowing how to avoid it is essential to protect your reputation as a sender.
How does snowshoe spamming impact the reputation of senders?
Snowshoe spamming is based on a simple principle: instead of sending a large volume of emails from a single IP address (which would trigger alerts), spammers distribute their mailings over several IPs and domains. The objective? To dilute their footprint and avoid detection by email providers.
The name comes from the snowshoe: instead of exerting strong pressure on a specific point, the weight is dispersed over a large surface area, thus complicating detection.
Methods used by spammers
- Purchase of multiple domains and IP addresses to distribute mailings
- Variation of sender email addresses to avoid blocking
- Sending of small volumes per IP
- Subtle modification of content to circumvent semantic filters
Email service providers such as Gmail, Outlook and Yahoo analyze and update their algorithms to detect these practices. But this process can also impact legitimate senders who use multiple IPs to optimize their campaigns.
Why can even legitimate senders be impacted?
Spam filters don’t just analyze the content of emails. They also evaluate criteria related to the sending infrastructure, sending habits and recipient engagement. A sender who regularly changes IPs, sends variable volumes or uses too many domains can be considered a Snowshoe spammer.
Sites such as Spamhaus and Google Postmaster Tools compile this data and assign a reputation rating to domains and IPs. A negative reputation can lead to lower deliverability rates and cause your emails to end up in spam.
One of the most problematic factors is shared IPs. When several companies share the same IP range, they collectively inherit its reputation. If one of the senders adopts dubious practices, all users of that IP can suffer the consequences. There is therefore an increased risk of being spammed or blocked completely. Companies using an email provider with a poor reputation are also vulnerable, as they can be associated with infrastructures identified as problematic.
Finally, the proliferation of sending domains can also work against senders. Frequently changing your main domain, using subdomains with no reputation history, or sending from multiple domain names without a clear strategy can arouse suspicion and damage deliverability.
How can you avoid being penalized for suspected snowshoe spamming?
To avoid being accused of “snowshoe spamming”, you need a stable sending infrastructure and a clear dispatch strategy.
Emails must also be sent gradually and regularly. A sudden increase in the volume of emails sent or too frequent a change of domain can be perceived as suspicious signals. It is advisable to establish a reputation history by maintaining a constant volume and limiting the number of changes to your infrastructure.
Email authentication plays a key role in validating the legitimacy of a sender. The implementation of SPF, DKIM and DMARC protocols proves that the emails sent are legitimate and have not been spoofed. Incorrect configuration of these protocols can result in a high rejection rate and negatively impact deliverability.
Always keep an eye on the reputation of your domain and your IPs. There are super practical tools such as Talos Intelligence, MXToolbox or Google Postmaster Tools that help you monitor how your reputation evolves and identify alerts upstream.
📌 Google Postmaster Tools: Analyzes the reputation of your domain and the impact on Gmail.
📌 Talos Intelligence (Cisco): Checks whether your IP is perceived as suspicious by email providers.
📌 MXToolbox & Spamhaus: Detects whether your IP or domain appears on a blacklist.
If your reputation is classified as “Poor” or “Bad”, action is needed.
Shared IPs and Snowshoe Spamming: An Underestimated Risk
When you use a shared IP, you share your reputation with other senders. It is a practical and economical solution, but it can also be a problem if some users of this IP adopt dubious practices, including Snowshoe Spamming.
If a spammer uses your shared IP to send out spam and circumvent anti-spam filters, this can impact the entire reputation of the IP address, including yours. The result? Your emails may be blocked or end up in spam, even if you follow all best practices.
Snowshoe Spamming: How Do Email Providers React?
The main email providers such as Gmail, Outlook and Yahoo have a zero tolerance policy towards Snowshoe Spamming, constantly strengthening their anti-spam filters. If your reputation as a sender is compromised, your emails may never reach the inbox. It relies heavily on user engagement (opens, clicks, replies) to assess the legitimacy of senders.
Test and audit your email deliverability
To ensure the effectiveness of your campaigns, it is important to check where your email campaigns actually end up. Specialized tools such as GlockApps allow you to simulate sending to different email providers and analyze their placement in the inbox, spam box or promotions tab. For their part, platforms such as Litmus offer a preview of how your emails will render on several email clients, thus guaranteeing an optimal experience for your recipients.
In the event of a sudden drop in your open rate or anomalies in the receipt of your messages, a full audit of your infrastructure is necessary. This includes verification of your authentication protocols (SPF, DKIM and DMARC), analysis of your IP addresses and domains, as well as optimization of the initialization of new IP addresses to avoid any potential blockages.
Don’t let these problems affect your performance. At MailSoar, we conduct in-depth audits to identify and resolve the factors limiting your deliverability. Contact us today for a detailed diagnosis and recommendations tailored to your business.
MailSoar: Your ally in avoiding errors and improving your deliverability
The deliverability of emails can quickly become a headache. Between spam filters, IP management and sender reputation, it is sometimes difficult to understand why certain emails do not arrive in the inbox.
We analyze your email infrastructure to identify areas for improvement, whether it’s a technical configuration, a bad reputation or a risk of being assimilated to Snowshoe Spamming. Then, we implement appropriate solutions to stabilize your deliverability and ensure that your messages reach their recipients.
If you have any doubts about your sending performance or want to avoid problems with being classified as spam, we are here to help. Contact us and let’s see together how to improve your deliverability.
