Build vs. Buy

Integrate every email service provider into your application faster with the Nylas API.

Get Free API Key

Connect Your App to Every Inbox in Minutes, Not Months

Communications features are table stakes for modern applications — but how you go about building the integration will have massive impact on your time to market and revenue.

When connecting your application to user’s email service providers like Gmail, Microsoft Exchange, and the rest, consider factors like security implications, ongoing maintenance and support costs, and opportunity costs.

Nylas Build vs Buy Connect App

Risks to Building Your Own Email Integration

Opportunity cost of time not spent building other features.

Takes as long as six months or more to implement and requires subject matter expertise.

Costly, time-consuming security & compliance certifications.

The burden of security infrastructure falls on you.

Should I Build?

Should I Buy?

Connecting your application to just one email service provider (ESP) can take months, and each ESP has its own unique set of protocols and specifications that you’ll have to build around:

Gmail Integration

Simple features like recurring events, sync & send for email attachments, and accommodating time zones for calendar events all require a special eye for detail as they don’t follow standard convention. If these features aren’t properly accounted for, users will miss important meetings, costing your customers time and money. In addition, Google’s strict security standards demand additional weeks or months of development time.

Total time to integrate: 3-6 months for a team of 4 engineers plus ongoing maintenance and security costs.

Microsoft Exchange Integration

With three different protocols, simply scoping out which one serves your user’s needs best is a task in its own. Documentation for Exchange ActiveSync (EAS), Exchange Web Services (EWS), and Graph amount to hundreds of pages each, with a handful of breaking changes introduced each year. Integrating with Microsoft Exchange also requires developers to integrate with outdated formats like WEBXML, when they could be spending time building features they’re more passionate about.

Total time to integrate: 3-6 months for a team of 4 engineers.

Office 365 Integration

The Office 365 APIs are built on legacy protocols with archaic structures, and they don’t come with out-of-the-box features like email analytics. You’ll need a small team to specialize in EWS, EAS, or Graph to build this integration.

Total time to integrate: 3-4 months for a team of 4 engineers to build a feature-limited integration. Integration

Supporting different deployment combinations of on-prem servers and cloud servers for Microsoft products creates complexities for development teams of any size.

Total time to integrate: 2-3 months for a team of 4 engineers.

IMAP Integration

Building an IMAP implementation will add only email functionality to your app. If you want to support any calendar or contacts sync, you’ll need to parse CalDav and CardDAV objects and return them in a consistent way to match the way you handle other ESPs.

Total time to integrate: 6-12 months for a team of 4 engineers to integrate with the core IMAP providers like iCloud, Fastmail, Yahoo,, and Dovecot.


There are a few costs to consider when evaluating whether to build or buy an integration between your application and ESPs:

  • Costs of operating servers at scale.

  • Support costs troubleshooting user errors and bugs.

  • Ongoing maintenance costs with new API versioning and breaking changes.

  • Security costs for compliance certifications like GDPR, SOC-2, Privacy Shield and more.

  • Opportunity cost of time not spent building other core features.

As your platform scales and your user base grows, these costs increase over time.

Nylas API Diagram

You can save months of engineering time and years of ongoing support by buying an API.

Should I Buy?

Integrating With the Nylas API

If you want to go to market faster with an email integration, integrating with a fully supported, universal API is the way to go. The Nylas API was created by developers, for developers, and powers a connection to 100% of email service providers in the world.

The Nylas API for Email, Calendar, and Contacts

The Nylas API connects apps to 100% of email service providers in as little as four lines of code. Save as much as 12 months of development time and focus on other critical features.

Save Valuable Engineering Time

Save months of engineering team time by building on top of the Nylas Email API.

Integrate Once; Connect With Many

Get bi-directional sync and full features across 100% of email, calendar, and contact providers.

Beat the Competition

Go to market faster with full email, calendar, and contacts features users love.

Reduce Costs

Eliminate initial build and ongoing maintenance costs of building a solution yourself.

Enterprise-Grade Security

Data for each account is fully encrypted and isolated with multi-level permission checks.

Six Questions To Help You Decide Whether to Build or Buy

How urgently do you need to build email and calendar functionality into your application?

The fastest option is to integrate with the Nylas Universal Email API.

Build vs buy: which approach sets you up for success in the long-term?

Using the Nylas Universal APIs abstracts away the complexity of building and maintaining integrations yourself, allowing your team to stay focused on building other core features.

What is the total cost of building an integration directly with providers (not using the Nylas API)?

It varies depending on the complexity of your integration, how secure your integration is, and how many users you have. Leading software companies choose Nylas as the most secure, performant solution with the highest ROI.

What if the person or team who builds the integration leaves your company?

You could lose institutional knowledge and spend months of time onboarding new engineers to the project. With the Nylas API, knowledge is never lost — everything is accessible through our docs.

What if you only need to support one service provider?

The costs of security, specialization in service specific protocols, and the initial build costs should all be considered. Even the simplest, most modern email service providers requires months of time to build a POV, publicly launch, and maintain over-time.

What if you only need to integrate with one part of the inbox (email, calendar, OR contacts)?

The biggest time demand is in building and maintaining your integration over time – integrating with just one part of the inbox can sometimes be just as complex as integrating with all three.

Ready to Start Building?