Email Deliverability Specialist

About

Customer.io

Over 9,000 companies — from scrappy startups to global brands — use our platform to send billions of emails, push notifications, in-app messages, and SMS every day.

Customer.io powers automated communication that people actually want to receive. We help teams send smarter, more relevant messages using real-time behavioral data.

About the role

Hi, my name is Caitlin, Senior Manager, Technical Support at

Customer.io

, and I'm looking for an Email Deliverability Specialist to join our deliverability program within Technical Support. You'll help customers reach the inbox by diagnosing sending issues, advising on best practices, and guiding senders through an email ecosystem that keeps changing.

You'll be one of several deliverability experts on a team that shares knowledge across Technical Support, so your work reaches well beyond your own queue. You'll partner with Customer Success, Technical Support, and Engineering: taking customer calls, equipping CSMs for customer conversations, working through complex technical cases alongside Engineering, and turning what you see in tickets into documentation, training, and better processes.

You'll thrive here if you think about the health of the whole program, enjoy improving how work gets done, and are equally comfortable digging into a detailed case and having a direct conversation with a customer about acceptable use.

What we value

Empathy and curiosity:

You approach every customer with patience and a desire to dig deeper, especially when a conversation gets uncomfortable.

Clarity:

You explain complex technical concepts simply and help others do the same.

Collaboration:

You build strong partnerships across Support, Customer Success, and Engineering, and you treat customer outcomes as a shared goal.

Thinking at scale:

You look at how we do things today and see what could work better for the whole organization, then you help make it happen.

Continuous learning:

You stay ahead of evolving standards and see change as a chance to improve how we work.

What you'll do

• Act as a trusted deliverability advisor to customers, handling complex cases through to full resolution and leading customer calls when a conversation needs it
• Audit sender setup and monitor reputation across IPs and domains, using authentication (SPF, DKIM, DMARC) and BIMI, DNS configuration, and provider tools like Google Postmaster Tools, Yahoo Sender Hub, and Microsoft SNDS to diagnose blocklists, spam traps, and engagement drops
• Work through highly technical issues with Engineering, taking ownership of the investigation first and sharing trends from customer cases with Product and Engineering
• Identify acceptable use policy violations and spam complaints, hold clear and direct conversations with customers about compliance, and keep up with evolving standards (Gmail and Yahoo sender requirements, CAN-SPAM, GDPR)
• Equip CSMs and Technical Support with the knowledge to handle deliverability conversations, through coaching, documentation, and training
• Improve processes, tools, and one-to-many resources, such as help content, Academy course and proactive customer guidance, so deliverability support scales across the organization

What we're looking for

• 2-4 years of experience in email deliverability at a mid-size or large ESP, B2B SaaS company, or marketing automation platform, with exposure to deliverability at scale
• Deep understanding of email authentication (SPF, DKIM, DMARC, BIMI) and infrastructure (SMTP, MTAs, DNS), with the technical comfort to work through complex issues with Engineering
• Proficiency with provider data feeds (Google Postmaster Tools, Yahoo Sender Hub, Microsoft SNDS) and third-party deliverability monitoring tools like Everest, MXToolbox, or similar, and the analytical skill to turn bounce, engagement, and blocklist data into clear recommendations
• Working knowledge of email compliance and acceptable use standards, and comfort having direct conversations with customers who are sending outside of them
• Experience building or improving processes, documentation, or training that help a support or deliverability team scale
• Excellent written and verbal communication, including comfort leading customer calls and simplifying technical concepts for any audience
• Located in the United States or Canada
• Bonus: participation in deliverability communities (M3AAWG, ESPC, or similar) and experience partnering with Customer Success teams