Email Expert Talk 2: Jennifer Nespola Lantz, Director of Deliverability at Zeta Global

In our series 'Email Expert Talk' we discuss all things email with distinguished experts who know about the struggles and strategies of working with high volume emails. We talk about how they cope with daily challenges, what their opinions are on the latest industry developments and how they manage to stay on top of the ever-changing email landscape.
For the second edition of Email Expert Talk, we reached out to Jennifer Nespola Lantz, Director of Deliverability at Zeta Global. No less than 15 years ago, Jennifer made a jump into the world of email - and has never left since. At the CRM Division of Zeta Global, Jennifer helps Fortune 1,000 and large middle-market companies get the most out of their email program by offering strategic advice and guidance on deliverability.
It's hard to overlook her passion for email when you hear her talk about her experiences in the field. One of the things she enjoys the most, is the open space that it brings, in which she and her industry peers are constantly learning from each other and supporting one another. In lieu of that, Jennifer gladly shares her own stories and advice with us in our Email Expert Talk series! Read on to find out how she copes with changes, how she stays informed of the latest trends and how she deals with deliverability issues.
What does a typical day at work look like for you?
Jennifer: "Each day in deliverability brings a new challenge. I can’t say there is a typical day, but my focus is often spread across troubleshooting delivery and inboxing problems. I also work on enhancing product features, auditing bounce logic, monitoring industry updates, and educating our clients on best practices. My goal is to help our clients get the most out of their email programs. It’s satisfying when you can get their campaigns to perform at a higher level especially when they’ve been struggling or when they didn’t even realize they had a problem."
It's satisfying when you can get campaigns to perform at a higher level.
"I think one of my favorite things to do though is to collaborate with industry peers about what’s going on in the deliverability world. It’s a wonderfully open space to ensure you are constantly learning and also supporting one another with either approaches, advice, experience and trends, amongst others."
What are the most common deliverability challenges you encounter in your work and how do you tackle them?
Jennifer: "'Bulking at Gmail and Microsoft seem to be the topic of most of the deliverability issues we receive. If I detailed out all the things we go through to tackle these - and the different scenarios for each sender - it would likely leave us sitting together for hours."
"The first thing I check when I encounter an issue, is how the sender is collecting emails - as well as if they are only mailing opt-in customers. Then I move on to, 'How long has this been going on? Are you sending consistently and with consistent volumes? When this started, did anything change (content, targeting, list source, etc.)?' At this point, I often find that most senders have changed something with targeting. In some cases, I will discover the sender has a setup that is hurting them. For example, they are using too many IPs and their mailings don’t have enough volume of consistency to build up a send history that can hold a reputation."
Data and targeting are probably the foremost culprits for deliverability issues.
"Most issues though, are often the result of a 'tired' list, an expanded audience, mailing to those that haven’t engaged for a while or a group that was suppressed for some time. Data and targeting are probably the foremost culprits for deliverability issues. In some cases, content can play a role. This is especially the case if it contains images/URLs that utilize domains with poor reputations or lead to questionable sites or infected sites, etc.”
When it comes to targeting, the solution is typically to scale back.
"When it comes to targeting, the solution is typically to scale back. The degree [of scaling back] really depends on the severity of the issue, but you can start at 3-6 months. This will help you concentrate on those [subscribers] that will behave more favorably versus those that complain or just dilute the good signals by doing nothing. The concentrated metrics are clear signals to the ISP that what you are sending is the good stuff. If there are reputation issues building, a sender has to prove that they are actually taking the right steps forward before their situation will change for the long haul."
A single good day doesn’t override weeks or months of less than desirable activity.
"It's a continuous process, a single good day doesn’t override weeks or months of less than desirable activity. It can take anywhere from 3-4 weeks to get your foot back in the door and a couple of months to truly rebuild (if reputation was severely impacted). Once a sender can reestablish themselves as a clean sender, they can start to expand and recoup some of their trimmed subscribers. However, they will likely find that a cap is needed at some point and they may not ever get to the point where they can mail to their list the same way they once did. Instead they may have to customize and be selective on when they expand. In some cases, they should look into re-permissioning a group to permanently weed out those who should go."
What result/performance data do you most rely on for tuning your delivery settings?
Jennifer: "For delivery issues, we heavily rely on SMTP messages and monitoring rates of delivery versus bounces and types of bounces. We can then identify if a client needs tuning in their current settings especially if they have changed their approach. For example, if we have a sender that is now pushing significantly more volume, we can evaluate the quality of that volume to see if deferrals are due to that or if we need to discuss IP makeup or review current connection settings if list composition by ISP has changed or if we need to revisit warming, etc."
"For deliverability issues, although they aren’t perfect and they aren’t all reliable, we start by looking at basic campaign metrics, reputation data from postmaster and reputation sites as well as blocklists, and, when available, inboxing rates. Campaign metrics include open rates, delivery rates, click rates, unsubscribe rates, complaint rates, and volumes. Focusing on one metric or data source alone makes it difficult to step back and really see the whole picture. Additionally, you may be solving issues for the wrong cause. That's why I first look at the overall picture, then at campaign/stream level, and then at the ISP level."
"I don’t focus on one point in time, but I will look back over a week, month, 6 months, etc. Trending over time and comparisons across campaigns, ISPs, etc. are important to determine whether the issue was an unfortunate campaign that didn’t perform well, whether it was flagged by filtering, or whether there is a pervasive issue that needs to be addressed. Again, all data points are important as you’ll find that sometimes one paints a grim picture, while another looks swimmingly. In some scenarios, I’ll also compare trending across our client base to identify if there were potential changes or issues at an ISP that impacts all traffic. Metric review will key you in and point you into the direction you need to go."
What advice would you give to someone who is just starting out in email deliverability?
Jennifer: "Read. Read blogs and then read some more. There are some amazing experts out there that share their knowledge about current issues freely, so take advantage of their brain power. I would also suggest that you make sure you research what you hear, discuss what you see, and be open to different thoughts, including your own."
Research what you hear, discuss what you see, and be open to different thoughts, including your own.
Where do you see email deliverability in 2025? What new challenges will we be facing and what current issues may be tackled by then?
Jennifer: "The great minds in this space always end up surprising me in what is being rolled out next. With regards to these new developments, what some may see as a challenge are - for the most part - beneficial to everyone. However, this often comes with some level of change, be it with how you view reporting, how customer relations will be altered, or how you send mail. Change is always a challenge."
The push to protect and help customers will continue to be the top priority.
"In the next 5 years, the push to protect and help customers will continue to be the top priority. I can’t quite imagine yet where the innovation will go. However, I’m sure the trend of optimizing the way we interact with email in the most intuitive way will continue. I doubt ISPs will only focus on delivering mail, they will also focus on improving the experience. That includes making sure that customers don’t see mail that will interfere with that experience. It could also manifest in putting more emphasis on authentication methods, like DMARC, and protecting privacy even more."
ISPs want to help senders, but both parties have to put in the effort .
"ISPs want to keep their customers happy and safe, but they understand that if they close the channels to monitoring performance - or if they become too much of a closed box - it’ll be difficult for any sender to determine who wants what in their inbox. Features like Verizon Media Group’s new data feeds or additional postmaster information or access can help with that in some respect. From my conversations with peers and ISPs, ISPs want to help senders, but it’s a symbiotic relationship so both parties have to put in the effort."