Why do Cheetah Digital emails have different headers based on the sending platform?
Matthew Whittaker
Co-founder & CTO, Suped
Published 12 Aug 2025
Updated 19 Aug 2025
7 min read
When examining email headers from a single sender, it's natural to expect a degree of consistency, especially if they use a major Email Service Provider (ESP) like Cheetah Digital. However, discovering significant differences in headers, such as an X-Mailer header in one email and only an IP lookup identifying the ESP in another, can be quite puzzling. This discrepancy often points to underlying complexities within the ESP's infrastructure.
The reason for these varying headers, even from a seemingly unified platform like Cheetah Digital, often stems from the evolution of large marketing technology companies. Many ESPs grow through acquisitions, integrating various platforms into their ecosystem. This can result in multiple legacy and modern sending systems operating simultaneously under the same brand, each with its own technical signature reflected in email headers. Understanding these nuances is crucial for email deliverability professionals.
The evolution of ESP platforms
Email Service Providers (ESPs) frequently expand their offerings and customer base by acquiring other companies and their respective email platforms. This strategy allows them to quickly integrate new features, technologies, or client portfolios. However, this often leads to a complex infrastructure where multiple distinct sending engines or platforms coexist.
Migrating all clients and functionalities from a legacy system to a newer, unified platform can be a massive undertaking. It often involves significant technical challenges, resource allocation, and potential disruption for clients. As a result, many ESPs opt to maintain and operate these different platforms in parallel for an extended period, or even indefinitely for specific client needs or functionalities.
Cheetah Digital (now part of Marigold) is a prime example of this phenomenon. They operate a legacy system, often referred to as CheetahMail, alongside their more modern offerings like the Marketing Suite (formerly CCMP, or Customer Engagement Platform). Each of these platforms has its own set of configurations, infrastructure, and default email header inclusions, leading to the variations observed.
Understanding email headers
Email headers are essentially the routing information and metadata attached to every email. They provide a trail of where an email originated, what servers it passed through, and details about its content and sending mechanism. Key headers that reveal information about the sending platform include Received headers and X-Mailer. The Received header shows the IP addresses and hostnames of the servers that processed the email, starting from the last server to the first.
The X-Mailer header is a non-standard (or X- header) field that often indicates the software or system used to send the email. While it's not mandatory, many ESPs include it as a standard practice for their specific platforms. For instance, an email sent via one version of Cheetah Digital's platform might explicitly state X-Mailer: CheetahMailer, whereas another platform within their ecosystem might omit this header entirely, requiring you to infer the sender from the Received headers and corresponding IP addresses.
Delivered-To: promotabtesting@gmail.com
Received: by 2002:a02:9247:0:0:0:0:0 with SMTP id y7csp603087jag;
Fri, 31 May 2019 07:55:27 -0700 (PDT)
X-Google-Smtp-Source: APXvYqzs3rMIWTONBqkxjM++FNaKuEfI6NOweDG9JdynNvAwhEEDzYxq82Tuhf/e/P8kIWRKfsr0
X-Received: by 2002:ac8:2a05:: with SMTP id k5mr9347200qtk.304.1559314527637;
Discrepancies in Cheetah Digital headers
The variance in headers for Cheetah Digital emails, specifically between clients like American Eagle and Eddie Bauer, can be attributed directly to the use of different underlying platforms within their suite. One client might be operating on CheetahMail, the legacy system, while another has migrated to or started on the newer Marketing Suite.
CheetahMail, being an older platform, may consistently include the X-Mailer: CheetahMailer header as part of its standard email generation process. In contrast, the Marketing Suite, a more modern platform, might be configured differently. It may not include a specific X-Mailer header, or it might use a different X- header altogether, relying more on the IP addresses in the Received headers for identification. This is a common architectural choice for ESPs that manage multiple generations of their software.
This situation highlights that a single ESP brand can represent a federation of different sending systems. The specific platform used by a client can influence various aspects beyond just headers, including campaign configuration options, reporting capabilities, and even the nuances of email authentication setup like SPF, DKIM, and DMARC.
CheetahMail (Legacy platform)
Headers: Often includes explicit X-Mailer headers identifying the platform.
Infrastructure: May use older IP ranges or server configurations.
Client Migration: Some long-standing clients may remain on this platform.
Marketing Suite (Modern platform)
Headers: May not include an X-Mailer or use a different proprietary one.
Infrastructure: Uses newer, optimized sending configurations and IP ranges.
Sales Focus: The primary product offered to new and migrating clients.
Impact on deliverability and best practices
For the most part, the presence or absence of an X-Mailer header itself has little to no direct impact on email deliverability. Mailbox providers primarily focus on standard authentication protocols like SPF, DKIM, and DMARC, as well as sender reputation metrics. However, the underlying platform, as indicated by these headers, can have an indirect influence. Different platforms might have different default settings for email authentication or manage their IP pools in distinct ways, which could subtly affect inbox placement.
It's important for senders to ensure that, regardless of which internal platform within Cheetah Digital (or any other large ESP) they are using, their email authentication records are correctly set up and aligned. This includes proper SPF records, DKIM signatures, and a robust DMARC policy. Consistent authentication builds trust with mailbox providers and is far more critical than an X-Mailer header.
Monitoring your domain's reputation across all sending platforms is also vital. A blocklist (or blacklist) listing on one set of IPs or domains associated with a legacy platform could affect overall email deliverability. While sending from multiple platforms is common, ensure that each platform adheres to best practices to maintain a strong sender reputation.
Key considerations for senders
Authentication: Always ensure your SPF, DKIM, and DMARC records are correctly configured for all sending domains and subdomains, regardless of the specific internal ESP platform used.
Reputation monitoring: Regularly check your IP and domain reputation. Even if your ESP handles the infrastructure, knowing where your emails are landing and why is critical for email deliverability.
Understand your setup: Work closely with your ESP to understand which platform your campaigns are being sent from and how that might impact headers and technical configurations. This knowledge is key for technical solutions for top-performing senders.
Views from the trenches
Best practices
Ensure SPF, DKIM, and DMARC are robustly implemented across all sending platforms, aligning with domain reputation best practices.
Maintain consistent branding in your 'From' name and address to reinforce sender identity, regardless of the backend system.
Regularly monitor your email deliverability rates and sender reputation across all IPs and domains used by your ESP.
Engage with your ESP's support to understand the specific technical configurations of each sending platform you utilize.
Common pitfalls
Assuming all emails from a single ESP brand share identical technical footprints and header structures.
Neglecting to verify email authentication settings for each distinct sending platform used by your organization.
Overlooking the potential for different blocklist (or blacklist) exposures based on varied sending IP ranges for different platforms.
Failing to track deliverability performance per sending platform, which can hide underlying issues.
Expert tips
Always inspect the full email headers for critical information, as the visible 'From' address can be misleading.
Focus on the 'Return-Path' and 'Authentication-Results' headers for authoritative information about where the email originated and its authentication status.
Understand that ESPs often have acquisition-driven infrastructures, which means multiple systems run simultaneously.
Leverage DMARC reports to gain comprehensive insight into authentication results across all your sending sources.
Expert view
Expert from Email Geeks says Cheetah Digital uses their CCMP platform (now Marketing Suite) alongside a legacy platform. This explains the observed differences in headers, as each platform has distinct characteristics.
2019-06-03 - Email Geeks
Marketer view
Marketer from Email Geeks says it is common for major ESPs to have multiple systems due to acquisitions, mentioning Oracle's Eloqua, Responsys, and Bronto as examples of this practice.
2019-06-03 - Email Geeks
Understanding your ESP's infrastructure
The phenomenon of different email headers from the same ESP, as seen with Cheetah Digital, is a common outcome of growth and acquisitions in the email marketing industry. Large ESPs often manage multiple underlying platforms, each with its own technical footprint, which is then reflected in the email headers you observe.
While an X-Mailer header itself typically doesn't impact deliverability, understanding the specific platform your emails are sent from is crucial for troubleshooting and ensuring consistent email authentication and sender reputation. Always prioritize proper SPF, DKIM, and DMARC configurations across all your sending sources.
Cheetah Digital, often stems from the evolution of large marketing technology companies. Many ESPs grow through acquisitions, integrating various platforms into their ecosystem. This can result in multiple legacy and modern sending systems operating simultaneously under the same brand, each with its own technical signature reflected in email headers. Understanding these nuances is crucial for email deliverability professionals.
