Deliverability Interviews – Sebastian Kluth from Certified Senders Alliance

Sebastian Kluth CSA

Interview 5: This is our fifth interview in the deliverability interview series. In this interview we spoke to Sebastian Kluth from Certified Senders Alliance (CSA).

Sebastian is an experienced email geek with a demonstrated history of working in the eCommerce and online industry since 2006. Skilled in digital strategy, online marketing, CRM and email marketing.

He is a strong consulting professional with IT background and and have large knowledge about tech and software especially in the CRM and email business. He also holds strong sales and account management skills, and team leading and coaching skills.

Sebastian works as a technical lead at CSA and he is based in Hamburg, Germany.

If you missed our earlier published interviews in the deliverability interview series you can read them here.

Interview Date: March 10, 2022

Postbox Services: Good Morning Sebastian, How are you doing?

Sebastian: I’m doing great, thanks. And thank you for your interest in the Certified Senders Alliance (CSA).

Postbox Services: Sebastian, could you introduce the Certified Senders Alliance (CSA) in general terms covering some history and how does CSA help certified senders?

Sebastian: The CSA was founded in 2004 as a project of eco – Association of the Internet Industry in cooperation with the German Dialogue Marketing Association (DDV). The idea behind it was to enable a system of self-regulation for the email industry. Senders comply with a standard of technical and legal criteria and, in return, get listed on a positive list of participating mailbox providers.

This system is still working today. Certified senders can promote their certification as proof of their professionalism towards their customers. They also benefit from benefits in deliverability and have access to tools that enable them to prevent damage on their platforms.

Postbox Services: Could you share some of the benefits mailbox providers and spam filter providers are getting with CSA participation? And how do they contribute back?

Sebastian: The whole principle of the Certified Senders Alliance is based on best practice criteria that we continuously define and publish. This is the fundamental basis of trust and transparency for the partnership managed by the CSA.

Mailbox providers (MBPs) trust that certified senders follow these criteria as they undergo an initial assessment and their compliance with the CSA criteria is constantly monitored. This accreditation based on high-level best practices allows mailbox providers to separate the traffic of trusted senders from other email traffic.

Certified senders get various benefits depending on the MBP. Different rate limits for delivery, easy FBL sign up, no or less IP warming efforts, lower filtering or enabling additional inbox features for better email usability are some of the major benefits. Certified senders also benefit from ready access to MBP knowledge and can better track any changing requirements. Regular events offered by the CSA bring MBPs and senders together and this platform creates an exclusive community that has the shared goal of improving the email ecosystem with benefits for all participants

Finally, the biggest asset for certified senders is to get access to exclusive MBP data feedback to monitor and optimise outbound email traffic and reduce spam on their own proactively.

Postbox Services: The CSA’s “Certification Monitor” dashboard shows quite granular compliance details for individual IPs and DKIM keys. I think this is very useful for any sender to have complete visibility on one dashboard. Does CSA get this data feed from all participating mailbox providers and is the data then consolidated at CSA end to be shown on the dashboard?

Sebastian: This first release of the CSA Certification Monitor is the starting point for a new way of thinking about certification.

As I said, transparency and trust are the keys to making email better. We are happy that some partners have already started sharing data with us to help create that transparency. Following the principle of “helping people to help themselves”, the MBP data provides the needed insights to determine bad email sending behavior from certain brands that enables the ESP to mitigate, trouble shoot and consult at an early stage.

The Certification Monitor isn’t a tool for inbox optimization, it is a tool to show violations against best practices with the expectation to improve or stop them.

Not all partners are sharing data with us, because of different reasons, but we are talking to all of them, and we will onboard more of them in the future.

The data is consolidated, and we will expand the analysis features further during 2022.

Postbox Services: Most of the ESPs now provide brands an option to go with dedicated Ips? Can ESPs get both shared and dedicated IPs certified with CSA?

Sebastian: It doesn’t matter if IPs are shared or dedicated, all IPs of a sender are included in the certification. The IPs of an ESP outline the scale of the sending infrastructure. The certified IPs create expected transparency from ESPs to MBPs by sending the message: “This is the infrastructure we send our best-practice-following emails from.” In other words, it is the technical footprint of an email sender.

Based on this technical scale, the ESP serves different brands. The key questions here is: “How is the ESP able to distinguish between the different brands, when it comes to deliverability and reputation trouble shooting and analysis?” Dedication makes it easier to differentiate, but IPs are limited. It is easier for ESPs to identify their sending brands/clients by their brand domain. That’s why the certification is based on IPs to ringfence the ESP, but the data monitoring is mainly set up based on DKIM Domains to help the certified ESPs identify their problematic email traffic by brand.

Postbox Services: You recently updated CSA criteria asking senders to comply with DKIM alignment. Were there many ESPs who were not in line with this requirement earlier and what was the need for this update?

Sebastian: The majority of certified senders already fulfil this criterion. From that point of view, DKIM alignment isn’t something new to many of our senders. We are in close contact with certified senders who see it as a difficult-to-fulfil criterion for all of their clients – it will be a challenge for very small brands at certified senders with less technical expertise.

It is a list of reasons that finally made us decide to move the DKIM alignment from being just a recommendation to a mandatory criterion. Mailbox providers are greatly increasing their email filtering based on domains – so it is just logical to authenticate the header from the domain correctly and the only way to do that is with DKIM. As email fraud is constantly increasing and affecting brands, we need to have a serious push into domain-based anti-spam and email fraud protection – with DMARC and BIMI, for example. DKIM alignment is the starting point and entry level. When we really want to protect brands, SPF isn’t enough, especially when we have large shared infrastructures in mind. The domain is the clear and unique identifier for a brand and this is the item to include in all authentication and email filtering methods in the future.

Postbox Services: I see there are many “Other certified senders” listed on CSA’s website apart from “Certified ESPs”. Are these the high-volume senders who have in-house email servers and do not use any ESP?

Sebastian: Yes, that is correct. In our definition, a certified sender runs an email outbound infrastructure in their own name and responsibility. The majority are ESPs that provide their sending service with their email server to brands, but some brands still run their own sending infrastructure. So in our definition, those senders are both an ESP and a brand.

Postbox Services: Lastly,  Sebastian, what is your recommendation to brands about the metrics which should be used in 2022 to measure email deliverability success? Do you think click through rates properly represent deliverability (considering that click rates are also impacted by conversion issues)?

Sebastian: In my opinion, there isn’t just one list of metrics or a single KPI to consider. I’m afraid it is going to stay as complex in the future as it was up to now. Rather than a list of metrics, it should be understood as a funnel represented by different metrics along the journey of an email.

Basically, it all starts without any performance indicators. A dedicated email setup with well-chosen domains for sending and authentication is the best starting point. We talked about it when looking at DKIM alignment. Credibility and trust are based on the domain of a brand and this will lead to higher deliverability results on a long term view. Putting efforts in properly implementing DKIM, DMARC, and BIMI pays off, even before any emails are sent.

High double opt-in rates ensure the fundamental commitment of subscribers to receive emails from a brand. They also ensure a high level of quality of the data in the email list. This also more or less ensures a low bounce rate right from the beginning and reduces the risk of generating and hitting spam traps upfront. Bounce reporting and management is key at first. Bounce management represents the direct feedback from the receiving server. Analysing bounces, especially soft bounces are very often underestimated. This is where the sender gets information about blocks, rate limits, violations of policy and furthermore. Ignoring them will increase the issues.

Following the email funnel, we all come across engagement-based email decisions. Even though open rates are more and more questionable, I would still use this indication. Clicks are also an indication, but the main issues besides the technical limitations are the marketing and content-related impact. A low click rate can also be caused from a terrible email template without a call-to-action. Those two KPIs can be used as indicators but not as reliable KPIs for deliverability.

The spam clicks and spam click rate should be considered seriously, because this negative engagement affects mailbox providers’ filtering decisions much more so than open and click rates. Every sender should sign up for all available feedback loops and report on this data. In additional to bounces, this is the direct feedback coming from the receiver’s site and should be monitored.

Postbox Services: This was really a very insightful discussion. It is great to know how CSA helps senders and ISP/ESPs alike. We appreciate you took out time to talk to us. Thanks much.

If you need any help/consultancy related to email marketing, email deliverability or email infrastructure please reach out to us.