Summary
Evaluating an Email Service Provider (ESP) for deliverability before committing can be complex, as there isn't a simple universal metric to gauge an ESP's overall deliverability rate. Instead, a prospective client's own sending practices, domain reputation, and content play a much more significant role in inbox placement than the ESP itself. However, certain aspects of an ESP's infrastructure, policies, and support can influence your success, especially when operating on shared IP pools.
Key findings
- No single metric: ESPs do not possess a single, meaningful deliverability statistic that applies universally across all their clients. Deliverability is highly individualized and dependent on the sender's practices.
- Sender's responsibility: Your email program's flow, content, and list hygiene are the primary determinants of your email deliverability rates, regardless of the ESP chosen.
- Shared IP impact: On shared IP addresses, your deliverability can be influenced by the sending behavior and reputation of other clients utilizing the same IPs. However, dedicated IPs offer more control over your sending reputation.
- Technical capabilities: An ESP's technical features, such as support for custom domains for email authentication (DKIM) and tracking, are crucial for isolating and building your sender reputation.
Key considerations
- Focus on your program: The core question to answer is whether your email program will thrive on their platform, not just the ESP's general performance.
- Inquire about IP management: Ask detailed questions about how the ESP manages their shared IP pools and the policies they have in place to prevent abuse from other clients.
- Evaluate support: Assess the quality of their deliverability support. Will they provide guidance on improving your sending behavior, or do you have an existing deliverability consultant? Good support can be vital for diagnosing deliverability drops after migration.
- Check technical features: Prioritize ESPs that offer custom domain usage for various email components, including click tracking, image hosting, and DKIM signing, as this significantly impacts email authentication and deliverability insights. Review this email deliverability test for a general idea.
What email marketers say
Email marketers often find themselves in a challenging position when considering a new ESP, especially if concerns about 'low deliverability' arise. Their experiences highlight that while an ESP provides the platform, the ultimate responsibility for inbox placement largely rests with the sender's own practices and content.
Key opinions
- Own practices dominate: Most email marketers find that their own mail flow and content quality are the most significant factors influencing their deliverability, rather than the ESP itself.
- Shared IP risks: Marketers recognize that if they are on a shared IP, the ESP's ability to police the behavior of other clients directly affects their own sending reputation.
- Blame game: There's a common sentiment that marketers with poor email programs often incorrectly blame their ESPs for deliverability issues.
- Transition period: Unless an ESP is exceptionally poor, initial deliverability issues after switching platforms are often similar to those experienced previously, stabilizing after a transition.
Key considerations
- Identify your needs: Marketers should focus on whether a specific ESP's features and policies align with their particular email program's needs and sending volume.
- Understand infrastructure: It's important to understand the ESP's infrastructure, especially how they handle shared IP pools and what measures are in place to manage sender reputation across those IPs.
- Assess onboarding: Consider the ESP's onboarding process and how it sets clients up for deliverability success, which can be critical for retaining sender reputation during migration.
- Check shared client quality: If using shared IPs, marketers should try to inquire about the types of other customers on the same infrastructure and if their sending patterns are compatible. This is often debated in forums like Quora.
Marketer view
Email marketer from Email Geeks suggests that their understanding is deliverability is based on your domain and sending IP. If you own both, you should be in a good position. If you are on a shared IP, you should definitely ask questions about other companies on the same IP.
Marketer view
Email marketer from Email Geeks states that if you are sharing an IP with other companies using the same ESP, your deliverability will be affected by how well the ESP policies the behavior of all their clients on those shared IPs. This highlights the importance of asking how an ESP manages its shared infrastructure.
What the experts say
Experts in email deliverability offer a more nuanced perspective on evaluating ESPs. They emphasize that while an ESP's infrastructure is important, the client's own sending behavior, the ESP's policies, and the level of support provided are critical factors. The idea of an ESP having a universally 'low' or 'high' deliverability rate is often misleading.
Key opinions
- ESPs are platforms, not deliverability guarantees: Most ESPs, excluding truly egregious spam cannons, offer similar overall deliverability within a few percentage points. The user's sending practices are the dominant influence.
- Shared IP management is key: If using shared IPs, the ESP's policies on managing client behavior (and penalizing bad senders) directly impact the collective blocklist and sender reputation of the IP pool. An ESP's impact on dedicated IPs is different.
- Custom domain usage: Using custom domains for tracking and DKIM signing helps isolate your sender reputation from the ESP's other clients, allowing you to build your own reputation.
- Deliverability support matters: The quality of an ESP's deliverability support team, their service level options, and how they manage ISP communication are vital for long-term success.
Key considerations
- Deep dive into policies: Investigate the ESP's enforcement policies, onboarding processes, and their general approach to managing senders, especially those on shared blocklist infrastructures.
- Assess technical features: Confirm that the ESP offers robust technical features that allow for proper email authentication, such as SPF, DKIM, and DMARC configurations.
- Meet the deliverability team: Request a meeting with the ESP's deliverability support leader to ask specific questions about their reputation management across the platform. This is one of four professional tactics to evaluate an ESP.
- Evaluate customer quality: Consider the type of other customers the ESP attracts. An ESP with 'consistently low delivery rates' may simply have many clients with poor sending practices, which could impact your own IP and domain reputation if you are on shared infrastructure.
Expert view
Expert from Email Geeks indicates that ESPs don't truly have meaningful deliverability statistics in a general sense. He compares it to asking which gym has lost the most weight, implying that while some features contribute to success, the outcome is highly dependent on the user.
Expert view
Expert from Email Geeks states that unless an ESP is spectacularly poorly chosen, the delivery issues at a new one will largely be the same after a transition period. Your mail flow and content are the dominant factors in your delivery rates.
What the documentation says
Documentation from leading platforms and industry resources consistently highlights that evaluating an ESP for deliverability requires a focus on technical capabilities, best practices, and the support structure. It's not just about the ESP's reputation, but how it empowers senders to maintain their own.
Key findings
- Track record and features: Documentation advises prioritizing ESPs with a proven history of high deliverability rates and specific features that support email deliverability, such as authentication protocols.
- Infrastructure matters: Choosing an ESP with robust and reliable infrastructure is a foundational step for maximizing deliverability.
- Technical concepts: Key technical considerations during ESP evaluation include scalability, availability, and the ESP's approach to IT overhead for their clients.
- Deliverability testing: Effective email deliverability testing involves a combination of pre-deployment checks and using seed lists to assess inbox placement.
Key considerations
- Support for authentication: Ensure the ESP fully supports and provides guidance for implementing critical email authentication standards like DMARC, SPF, and DKIM.
- Documentation quality: Before choosing an ESP, review their documentation. It should be well-organized and allow you to easily find information on setup and deliverability best practices.
- Shared vs. dedicated IPs: Understand how the ESP manages shared IP pools and what options are available for dedicated IPs, and how this impacts reputation and blocklist monitoring.
- Testing capabilities: Look for ESPs that provide tools or guidance for testing email deliverability using seedlists and DMARC configurations. Salesforce outlines key deliverability best practices.
Technical article
Documentation from Salesforce Marketing Cloud emphasizes that when selecting an ESP, prioritize those with a proven track record in maintaining high deliverability rates. Look for features that support strong sender reputation and compliance.
Technical article
Documentation from Bluecore advises that when evaluating a new ESP, at a minimum, your IT team needs to assess four core areas: scalability, availability, IT overhead, and security. These technical aspects indirectly contribute to deliverability performance.
Related resources
7 resources
Related pages
How to diagnose email deliverability issues and prevent emails from going to spam?
How does email reputation transfer during IP warming with a new ESP, and how to resolve deliverability issues?
How to test email deliverability using seedlists and DMARC configurations?
How do ESPs impact deliverability on dedicated IPs?
How do SPF, DKIM, DMARC, and dedicated IPs affect email deliverability when using a third-party ESP?
What ESP capabilities are essential for email authentication and deliverability insights?
What are the best practices for migrating to a new ESP while retaining sender reputation?
How to run an email deliverability test: a proven checklist
An in-depth guide to email blocklists
A simple guide to DMARC, SPF, and DKIM
