Reply API Labs

Power up your product with business email sending capabilities to help your users scale personal communications with just a few lines of code.

Email Sending API

Enable your users to send personal or business emails at scale with Reply’s Email Sending API.

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Power up your product with email sequences

With Reply’s Email Sending API, users can connect personal or business email accounts to send email sequences, get replies, and track performance directly within your product.

Power up your product with email sequences

Benefit from white-label solution

Reply’s Email Sending API is a white-label, ready-made email sequence engine that you can implement seamlessly into your app while keeping its UI consistent.

Benefit from white-label solution

Scale up with compatible APIs

Email Sending API is fully compatible with other Reply APIs products:

  • AI Assistant API that detects buyer intent in emails and evaluates the probability of getting a response based on your email content;
  • Email Warm-Up API that helps users build up domain reputation and improve deliverability steering clear from the SPAM filters.
Scale up with compatible APIs

Secure integration with a trusted provider

Reply’s API solutions are Privacy Shield certified and GDPR compliant. The user data is encrypted and isolated with multi-level permission checks, providing a full control over what data you sync.

Secure integration with a trusted provider
  • A unified RESTful API

    A unified RESTful API

    Use a single API that works with major providers to bring email capabilities to your app.

  • Multiple email providers

    Multiple email providers

    Connect to Gmail, Microsoft Exchange,, IMAP with just a few lines of code.

  • Two-way data sync

    Two-way data sync

    Keep the user’s account data up to date with real-time, two-way synchronization.

  • Highest email deliverability

    Highest email deliverability

    Reply’s email sending engine is optimized for the best results, ensuring your emails reach the inbox.

  • Full control over account

    Full control over account

    Get access to both sent and received emails for included contacts via API.

  • Access to email content

    Access to email content

    Get email body text, sender and recipient information, subject lines, dates, pictures, etc.

  • Performance tracking

    Performance tracking

    Keep track of bounces, auto-replies, opt-outs, out-of-office messages, and link clicks via API or file.

  • Webhooks


    Use webhooks to build event-based workflows on top of Reply’s Email Sending API.

  • Single-Click Connect

    Single-Click Connect

    Easily connect Gmail or Office 365 accounts to Reply in just a click.

  • Dedicated CS and Support

    Dedicated CS and Support

    Reply’s CS and Support teams will be with you every step of the way, with 5 min response time in live chat.

  • Google OAuth verified

    Google OAuth verified

    Reply is Google OAuth verified solution. Need help with Google security verification? We can help.

  • Branded URLs

    Branded URLs

    Create branded URLs for you and your customers to use for link tracking, open and opt-out URLs.

Integrate emails in your stack now

Use Reply’s API to enable email sequencing within your apps.
Includes 24/7 help from a friendly and knowledgeable CS team.

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Frequently Asked Questions

How do I get started with Reply’s Email Sending API?

Reach out to us by clicking the [Contact Us] button on this page and schedule a call with Reply’s product expert. During the call, we will identify the specifics of your business case and come up with an appropriate solution to fit your needs.

What kinds of companies use Reply Email Sending API?

Reply’s Email Sending API would be a perfect addition to CRMs that doesn’t have the email sequencing functionality, recruiting applicant tracking systems (ATS), legal and financial (banking) products, marketplaces, educational institutions (universities and colleges).

How is the Email Sending API secured?

Reply’s Email Sending API is hosted in Microsoft Azure Cloud which provides robust, physical data center security and environmental controls. We encrypt sensitive user data both at rest and in transit over public networks and isolate it with multi-level permission checks, providing a full control over what data you sync via API.

How do my users activate email sync?

Your users can initiate a full email sync simply by granting Reply’s API the access to their account. To do that, they will need to input their credentials and then be redirected back to your application. For maximum ease of setup, Reply supports Single Click connect with Gmail., All rights reserved © 2018. sales@reply.ioContact sales +1 888 340 72 31 (toll free)