Services

About Us

Contact Us

THE WORLD’S FIRST EMAIL PERFORMANCE OPTIMIZATION AGENCY

Better reach with smarter sending

Sending Partners is the world’s first agency focused exclusively on Email Performance Optimization (EPO) — covering list health, deliverability, and inbox performance. We help brands reach more of the audience they already have by fixing the invisible systems that quietly limit growth.

By optimizing sender infrastructure, list quality, and behavioral signals, we uncover and resolve the hidden performance leaks that prevent emails from being seen — turning underperforming lists into high-performing revenue assets.

Talk to an Email Specialist

Talk to an Email Specialist

Platform Ready
Platform Ready

Our data-backed EPO services

Email Performance Optimization Services

Poor data leads to poor performance. Most email systems silently decay from the inside — bloated lists, low-quality leads, and decaying engagement patterns erode inbox reach and revenue. We find the hidden gaps, clean the data, and restore performance at the source.

More Details

Email Performance Optimization Services

Poor data leads to poor performance. Most email systems silently decay from the inside — bloated lists, low-quality leads, and decaying engagement patterns erode inbox reach and revenue. We find the hidden gaps, clean the data, and restore performance at the source.

More Details

Email Performance Optimization Services

Poor data leads to poor performance. Most email systems silently decay from the inside — bloated lists, low-quality leads, and decaying engagement patterns erode inbox reach and revenue. We find the hidden gaps, clean the data, and restore performance at the source.

More Details

Email Performance Optimization Services

Poor data leads to poor performance. Most email systems silently decay from the inside — bloated lists, low-quality leads, and decaying engagement patterns erode inbox reach and revenue. We find the hidden gaps, clean the data, and restore performance at the source.

More Details

Inbox Deliverability Optimization

Our flagship service. We audit, fix, and monitor your full deliverability stack — including DNS, domain reputation, sender setup, and warmup protocols. The result: maximum inbox placement and long-term sender health.

More Details

Inbox Deliverability Optimization

Our flagship service. We audit, fix, and monitor your full deliverability stack — including DNS, domain reputation, sender setup, and warmup protocols. The result: maximum inbox placement and long-term sender health.

More Details

Inbox Deliverability Optimization

Our flagship service. We audit, fix, and monitor your full deliverability stack — including DNS, domain reputation, sender setup, and warmup protocols. The result: maximum inbox placement and long-term sender health.

More Details

Inbox Deliverability Optimization

Our flagship service. We audit, fix, and monitor your full deliverability stack — including DNS, domain reputation, sender setup, and warmup protocols. The result: maximum inbox placement and long-term sender health.

More Details

Email List Hygiene + Segmentation

Clean lists convert better. We scrub your contacts, remove toxic addresses, segment by real engagement, and surface high-intent profiles. One pass improves deliverability, campaign results, and long-term list value.

More Details

Email List Hygiene + Segmentation

Clean lists convert better. We scrub your contacts, remove toxic addresses, segment by real engagement, and surface high-intent profiles. One pass improves deliverability, campaign results, and long-term list value.

More Details

Email List Hygiene + Segmentation

Clean lists convert better. We scrub your contacts, remove toxic addresses, segment by real engagement, and surface high-intent profiles. One pass improves deliverability, campaign results, and long-term list value.

More Details

Email List Hygiene + Segmentation

Clean lists convert better. We scrub your contacts, remove toxic addresses, segment by real engagement, and surface high-intent profiles. One pass improves deliverability, campaign results, and long-term list value.

More Details

Behavioral Optimization

Inbox placement is algorithmic — and engagement is the signal. We design smart behavioral flows, re-engagement loops, and micro-trigger sequences that build positive sender reputation automatically.

More Details

Behavioral Optimization

Inbox placement is algorithmic — and engagement is the signal. We design smart behavioral flows, re-engagement loops, and micro-trigger sequences that build positive sender reputation automatically.

More Details

Behavioral Optimization

Inbox placement is algorithmic — and engagement is the signal. We design smart behavioral flows, re-engagement loops, and micro-trigger sequences that build positive sender reputation automatically.

More Details

Behavioral Optimization

Inbox placement is algorithmic — and engagement is the signal. We design smart behavioral flows, re-engagement loops, and micro-trigger sequences that build positive sender reputation automatically.

More Details

Revenue-Focused Engagement Intelligence

We go beyond opens and clicks. By analyzing deep engagement patterns across domains and campaigns, we identify your most valuable subscribers — and optimize your sequences around who’s actually moving revenue.

More Details

Revenue-Focused Engagement Intelligence

We go beyond opens and clicks. By analyzing deep engagement patterns across domains and campaigns, we identify your most valuable subscribers — and optimize your sequences around who’s actually moving revenue.

More Details

Revenue-Focused Engagement Intelligence

We go beyond opens and clicks. By analyzing deep engagement patterns across domains and campaigns, we identify your most valuable subscribers — and optimize your sequences around who’s actually moving revenue.

More Details

Revenue-Focused Engagement Intelligence

We go beyond opens and clicks. By analyzing deep engagement patterns across domains and campaigns, we identify your most valuable subscribers — and optimize your sequences around who’s actually moving revenue.

More Details

Performance Analytics + Monitoring

We don’t guess — we track. Our custom dashboards go deeper than Klaviyo or Mailchimp, showing inbox placement, sender reputation, engagement decay, and list health in real-time.

More Details

Performance Analytics + Monitoring

We don’t guess — we track. Our custom dashboards go deeper than Klaviyo or Mailchimp, showing inbox placement, sender reputation, engagement decay, and list health in real-time.

More Details

Performance Analytics + Monitoring

We don’t guess — we track. Our custom dashboards go deeper than Klaviyo or Mailchimp, showing inbox placement, sender reputation, engagement decay, and list health in real-time.

More Details

Performance Analytics + Monitoring

We don’t guess — we track. Our custom dashboards go deeper than Klaviyo or Mailchimp, showing inbox placement, sender reputation, engagement decay, and list health in real-time.

More Details

Who we are

Sending Partners is the world’s first agency focused exclusively on Email Performance Optimization (EPO). We’re a tight-knit team of deliverability engineers, email infrastructure specialists, and data strategists — brought together to solve the overlooked performance layer of email.

From B2B lead gen to ecommerce brands, we’ve helped early clients protect sender reputation, improve list health, and unlock measurable revenue through smarter sending.

More about us

More about us

More about us

More about us

Why our clients choose us

Trusted by fast-growing brands

Startups, agencies, and ecommerce brands alike rely on us to protect their most overlooked asset — email reach. We’ve been called in to fix everything from Gmail spam issues, bloated decaying lists to Outlook delivery blocks.

It’s not just your list — it’s your delivery

Many teams blame low performance on poor lists — but the real issue often runs deeper. Bad list quality causes bad deliverability. We help fix both so more emails actually reach the people who matter.

Specialists, not generalists

We don’t do creative, copy, or design. We only fix the performance layer underneath it all. That’s why teams hire us to sit beside — not replace — their existing marketing team.

Custom diagnostics. Clear dashboards. Ongoing monitoring.

From day one, we give you visibility into where your emails are landing and why — and then we make sure it stays fixed.

Automation makes us scalable

Our proprietary workflows allow us to monitor inbox placement across Gmail, Outlook, Yahoo, and Apple Mail at scale. We also implement warming automations and response loops to repair and preserve sender reputation — faster than internal teams ever could.

We partner with the top tools in deliverability and email infrastructure

EPO agency
FAQs

What is an EPO agency?

An Email Performance Optimization agency, otherwise known as an EPO agency, is a specialist partner whose primary purpose is to improve your emails ability to reach, engage, and convert.

For example, maybe you run a B2B SaaS company and you’ve built a sizable list — but open rates are dropping, clicks are inconsistent, and replies are drying up. An EPO agency like ours helps you uncover what’s really happening behind those numbers. We go beyond your email platform to audit inbox placement, engagement patterns, technical reputation, and more.

Or maybe you run a DTC brand that relies heavily on email to drive returning customers. You might notice strong deliverability to Gmail but consistent issues with Outlook or Apple Mail. Through a combination of technical diagnostics, list hygiene, and behavior-driven segmentation, our team helps restore and protect your revenue from email — often uncovering hidden performance gaps your marketing platform can’t see.

What does an EPO agency do?

Why should you hire an EPO agency?

What differentiates Sending Partners from other agencies?

How quickly can Sending Partners generate ROI?

Can Sending Partners work effectively alongside your internal email or marketing team?

Should you hire an agency or build out your own internal team?

What is an EPO agency?

An Email Performance Optimization agency, otherwise known as an EPO agency, is a specialist partner whose primary purpose is to improve your emails ability to reach, engage, and convert.

For example, maybe you run a B2B SaaS company and you’ve built a sizable list — but open rates are dropping, clicks are inconsistent, and replies are drying up. An EPO agency like ours helps you uncover what’s really happening behind those numbers. We go beyond your email platform to audit inbox placement, engagement patterns, technical reputation, and more.

Or maybe you run a DTC brand that relies heavily on email to drive returning customers. You might notice strong deliverability to Gmail but consistent issues with Outlook or Apple Mail. Through a combination of technical diagnostics, list hygiene, and behavior-driven segmentation, our team helps restore and protect your revenue from email — often uncovering hidden performance gaps your marketing platform can’t see.

What does an EPO agency do?

Why should you hire an EPO agency?

What differentiates Sending Partners from other agencies?

How quickly can Sending Partners generate ROI?

Can Sending Partners work effectively alongside your internal email or marketing team?

Should you hire an agency or build out your own internal team?

What is an EPO agency?

An Email Performance Optimization agency, otherwise known as an EPO agency, is a specialist partner whose primary purpose is to improve your emails ability to reach, engage, and convert.

For example, maybe you run a B2B SaaS company and you’ve built a sizable list — but open rates are dropping, clicks are inconsistent, and replies are drying up. An EPO agency like ours helps you uncover what’s really happening behind those numbers. We go beyond your email platform to audit inbox placement, engagement patterns, technical reputation, and more.

Or maybe you run a DTC brand that relies heavily on email to drive returning customers. You might notice strong deliverability to Gmail but consistent issues with Outlook or Apple Mail. Through a combination of technical diagnostics, list hygiene, and behavior-driven segmentation, our team helps restore and protect your revenue from email — often uncovering hidden performance gaps your marketing platform can’t see.

What does an EPO agency do?

Why should you hire an EPO agency?

What differentiates Sending Partners from other agencies?

How quickly can Sending Partners generate ROI?

Can Sending Partners work effectively alongside your internal email or marketing team?

Should you hire an agency or build out your own internal team?

What is an EPO agency?

An Email Performance Optimization agency, otherwise known as an EPO agency, is a specialist partner whose primary purpose is to improve your emails ability to reach, engage, and convert.

For example, maybe you run a B2B SaaS company and you’ve built a sizable list — but open rates are dropping, clicks are inconsistent, and replies are drying up. An EPO agency like ours helps you uncover what’s really happening behind those numbers. We go beyond your email platform to audit inbox placement, engagement patterns, technical reputation, and more.

Or maybe you run a DTC brand that relies heavily on email to drive returning customers. You might notice strong deliverability to Gmail but consistent issues with Outlook or Apple Mail. Through a combination of technical diagnostics, list hygiene, and behavior-driven segmentation, our team helps restore and protect your revenue from email — often uncovering hidden performance gaps your marketing platform can’t see.

What does an EPO agency do?

Why should you hire an EPO agency?

What differentiates Sending Partners from other agencies?

How quickly can Sending Partners generate ROI?

Can Sending Partners work effectively alongside your internal email or marketing team?

Should you hire an agency or build out your own internal team?

How can you get in touch?

If you think your emails should be performing better — or you’re unsure why engagement is dropping — we’d love to talk.

Talk to an Email Specialst

Talk to an Email Specialst

Talk to an Email Specialst

Talk to an Email Specialst