FreeCustomEmail - Temp Email and OTP Testing API

FreeCustom.Email is a powerful API that enables users to generate temporary email addresses for seamless online registration and OTP testing. With its user-friendly interface, you can effortlessly create disposable email accounts to bypass spam and enhance privacy, while easily receiving one-time passwords and verification emails without any hassle. Ideal for developers and testers, this API ensures secure and anonymous interactions with online services.
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FreeCustom.Email is a robust and developer-friendly Temporary Email and OTP Testing API designed specifically for automating signup, authentication, and email-based workflows.

With this API, you can effortlessly create inboxes on demand, receive emails in real-time, and programmatically extract verification codes or links. This functionality makes it ideal for testing authentication flows, continuous integration (CI) pipelines, and automation systems.

Common use cases include:

  • Testing signup and login flows
  • Handling OTP-based authentication
  • Verifying password reset emails
  • Running end-to-end tests using tools like Playwright or Cypress

The FreeCustom.Email API is straightforward to integrate, making it perfect for developers building automation tools, quality assurance (QA) pipelines, or multi-account testing systems.


⚠️ Note on Marketplace Version

This marketplace version provides a simplified API experience tailored for quick implementations.

For access to the full capabilities, enhanced performance, and advanced features, consider using the direct API on our platform.


🚀 Available on Our Platform

Our direct API offers additional features and superior performance, including:

  • Automatic OTP extraction from incoming emails
  • Verification link extraction
  • Attachment support
  • Real-time inbox updates
  • Faster email delivery
  • More stable domains and higher deliverability rates
  • Lower pricing compared to third-party platforms
  • Faster feature updates and enhancements

FreeCustom.Email is specifically designed for developers who require reliable email infrastructure for testing and automation, with an emphasis on performance, simplicity, and real-world debugging capabilities.

API Documentation

Endpoints


Fetches all available free domains for use with the marketplace API.


                                                                            
GET https://www.zylalabs.com/api/12433/freecustomemail+-+temp+email+and+otp+testing+api/23570/get+domains
                                                                            
                                                                        

Test Endpoint

API EXAMPLE RESPONSE

       
                                                                                                        
                                                                                                                                                                                                                                                                                                                                        {"success":true,"data":[{"domain":"ditapi.info","tier":"free","tags":[]},{"domain":"ditcloud.info","tier":"free","tags":[]},{"domain":"ditdrive.info","tier":"free","tags":[]},{"domain":"ditgame.info","tier":"free","tags":[]},{"domain":"ditlearn.info","tier":"free","tags":[]},{"domain":"ditpay.info","tier":"free","tags":[]},{"domain":"ditplay.info","tier":"free","tags":["popular"]},{"domain":"ditube.info","tier":"free","tags":["popular"]},{"domain":"junkstopper.info","tier":"free","tags":[]},{"domain":"areueally.info","tier":"free","tags":[]},{"domain":"addmy.space","tier":"free","tags":["new"]},{"domain":"attachmy.site","tier":"free","tags":["new"]}],"count":12,"note":"Upgrade to Growth plan to access additional pro domains."}
                                                                                                                                                                                                                    
                                                                                                    

Get Domains - CODE SNIPPETS


curl --location --request GET 'https://zylalabs.com/api/12433/freecustomemail+-+temp+email+and+otp+testing+api/23570/get+domains' --header 'Authorization: Bearer YOUR_API_KEY' 


    

Retrieve all messages in the mailbox of a specific user


                                                                            
GET https://www.zylalabs.com/api/12433/freecustomemail+-+temp+email+and+otp+testing+api/23571/get+mailbox+messages
                                                                            
                                                                        

Test Endpoint

API EXAMPLE RESPONSE

       
                                                                                                        
                                                                                                                                                                                                                                                                                                                                        {"success":true,"message":"Mailbox retrieved successfully.","data":[{"id":"F7LpBSaAuG","from":"\"xAI\" <[email protected]>","to":"[email protected]","subject":"S3G-9PC xAI confirmation code","date":"2026-04-27T16:03:32.078Z","hasAttachment":false,"wasAttachmentStripped":false,"otp":"__DETECTED__","verificationLink":null},{"id":"B49mzFMnvx","from":"\"SendTestEmail\" <[email protected]>","to":"[email protected]","subject":"SendTestEmail.com - Testing Email ID: 808e9ed8a9d764cf7e918e536f7a8836","date":"2026-04-27T16:03:11.625Z","hasAttachment":false,"wasAttachmentStripped":false,"otp":null,"verificationLink":null}],"encryptedMailbox":"D-6ffejiz1jxh13cxkur"}
                                                                                                                                                                                                                    
                                                                                                    

Get Mailbox Messages - CODE SNIPPETS


curl --location --request GET 'https://zylalabs.com/api/12433/freecustomemail+-+temp+email+and+otp+testing+api/23571/get+mailbox+messages&email=Required' --header 'Authorization: Bearer YOUR_API_KEY' 


    

Get messages with id from mailbox name.



                                                                            
GET https://www.zylalabs.com/api/12433/freecustomemail+-+temp+email+and+otp+testing+api/23572/get+full+message
                                                                            
                                                                        

Test Endpoint

API EXAMPLE RESPONSE

       
                                                                                                        
                                                                                                                                                                                                                                                                                                                                        {"success":true,"message":"Message retrieved successfully.","data":{"id":"TWqYmjH-Ma","from":"\"SendTestEmail\" <[email protected]>","to":"[email protected]","subject":"SendTestEmail.com - Testing Email ID: fbe5dcfe22549d34c858582ea12d7d9b","date":"2026-04-27T06:02:03.785Z","hasAttachment":false,"wasAttachmentStripped":false,"html":"<html>\nCongratulations!<br><br>\nIf you are reading this your email address is working.<br><br>\nThis is not spam or a solicitation. This email was sent to your email address because you, or someone else, requested a test email to be sent to this address. We work hard to ensure a balance between testing, transparency, and privacy. If you did not request this email test, it's likely that someone accidentally mistyped their email address as yours. You can request your email address be blocked here: <a href=\"https://sendtestemail.com/block\">https://sendtestemail.com/block</a><br><br>\nThe IP address of the requester of this test email is: 103.175.29.77\n</html>","text":"If you are reading this your email address is working.\n\n\nThis is not spam or a solicitation. This email was sent to your email address because you, or someone else, requested a test email to be sent to this address. We work hard to ensure a balance between testing, transparency, and privacy. If you did not request this email test, it's likely that someone accidentally mistyped their email address as yours. You can request your email address be blocked here: https://sendtestemail.com/block\n\n\nThe IP address of the requester of this test email is: 103.175.29.77","attachments":[],"otp":null,"otpScore":null,"verificationLink":null}}
                                                                                                                                                                                                                    
                                                                                                    

Get Full Message - CODE SNIPPETS


curl --location --request GET 'https://zylalabs.com/api/12433/freecustomemail+-+temp+email+and+otp+testing+api/23572/get+full+message&email=Required&/message/=Required&id=Required' --header 'Authorization: Bearer YOUR_API_KEY' 


    

Delete a message with its id from mailbox name.



                                                                            
DELETE https://www.zylalabs.com/api/12433/freecustomemail+-+temp+email+and+otp+testing+api/23573/delete+a+message
                                                                            
                                                                        

Test Endpoint

API EXAMPLE RESPONSE

       
                                                                                                        
                                                                                                                                                                                                                                                                                                                                        {"success":false,"message":"Message not found or already deleted."}
                                                                                                                                                                                                                    
                                                                                                    

Delete a message - CODE SNIPPETS


curl --location --request DELETE 'https://zylalabs.com/api/12433/freecustomemail+-+temp+email+and+otp+testing+api/23573/delete+a+message&email=Required&/message/=Required&id=Required' --header 'Authorization: Bearer YOUR_API_KEY' 


    

Get details about number of queued and denied mailboxes.



                                                                            
GET https://www.zylalabs.com/api/12433/freecustomemail+-+temp+email+and+otp+testing+api/23574/get+health+and+stats
                                                                            
                                                                        

Test Endpoint

API EXAMPLE RESPONSE

       
                                                                                                        
                                                                                                                                                                                                                                                                                                                                        {"success":true,"message":"Stats retrieved successfully.","data":{"queued":2997900,"denied":122209}}
                                                                                                                                                                                                                    
                                                                                                    

Get Health and Stats - CODE SNIPPETS


curl --location --request GET 'https://zylalabs.com/api/12433/freecustomemail+-+temp+email+and+otp+testing+api/23574/get+health+and+stats' --header 'Authorization: Bearer YOUR_API_KEY' 


    

API Access Key & Authentication

After signing up, every developer is assigned a personal API access key, a unique combination of letters and digits provided to access to our API endpoint. To authenticate with the FreeCustomEmail - Temp Email and OTP Testing API simply include your bearer token in the Authorization header.
Headers
Header Description
Authorization [Required] Should be Bearer access_key. See "Your API Access Key" above when you are subscribed.

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FreeCustomEmail - Temp Email and OTP Testing API FAQs

The primary function of the FreeCustom.Email API is to generate temporary email addresses for online registration and OTP testing, allowing users to receive one-time passwords and verification emails securely and anonymously.

Developers can use the FreeCustom.Email API to create disposable email accounts that can receive verification emails during the signup process, enabling them to test the entire flow without using personal email addresses.

The API can extract one-time passwords (OTPs), verification links, and other relevant information from incoming emails in real-time.

Yes, the FreeCustom.Email API is specifically designed to handle OTP-based authentication by allowing users to receive and extract OTPs from emails.

Common use cases include testing signup and login flows, handling OTP-based authentication, verifying password reset emails, and running end-to-end tests using automation tools.

The API supports standard email formats, allowing users to receive and parse emails in plain text or HTML.

The FreeCustom.Email API provides real-time inbox updates, allowing users to receive emails instantly as they arrive.

The benefits include enhanced privacy, reduced spam, simplified testing of email workflows, and the ability to automate email-based processes without using personal email accounts.

Yes, the direct API version supports attachment handling, allowing users to receive emails with attachments.

The core value proposition is to provide a reliable and user-friendly solution for generating temporary email addresses, enhancing privacy, and facilitating seamless testing of email workflows.

The API can be integrated into CI pipelines by automating the creation of temporary email accounts and extracting verification codes during automated tests.

The API returns data fields such as sender, subject, body, timestamp, and any extracted OTPs or links from the email.

Yes, the FreeCustom.Email API is ideal for use with testing frameworks like Playwright or Cypress for running end-to-end tests involving email verification.

The API is designed for developers with a focus on performance, simplicity, and reliable email infrastructure for testing and automation.

The API utilizes stable domains and optimized delivery mechanisms to ensure higher deliverability rates for incoming emails.

The direct API version offers features like automatic OTP extraction, verification link extraction, attachment support, and faster email delivery.

By providing temporary email addresses, the API allows users to bypass spam and protect their personal email addresses from exposure.

Users can create a temporary email address by making a simple API call, which generates a unique inbox for receiving emails.

Yes, the API can be used to receive and verify password reset emails, making it easier to test this functionality.

The "获取域名" endpoint returns a list of available free domains for creating temporary email addresses. The response includes each domain's name, tier, and any associated tags.

The response includes fields such as "id," "from," "to," "subject," "date," "hasAttachment," and "otp." These fields provide essential details about each email message retrieved.

The response data is structured in a JSON format, containing a success status, a message, and a "data" object that includes detailed information about the specific email, such as sender, subject, and content.

The "删除消息" endpoint requires the "id" parameter, which specifies the unique identifier of the message to be deleted from the inbox.

This endpoint provides statistics on the number of queued and denied emails, offering insights into the email processing status and potential issues with delivery.

Users can parse the returned data to extract relevant information, such as OTPs or verification links, enabling automated testing of email workflows and authentication processes.

Typical use cases include retrieving detailed information about specific emails for debugging, verifying email content during tests, and extracting links or OTPs for automated processes.

The API employs mechanisms to ensure reliable email delivery and accurate data retrieval, including monitoring email processing and maintaining stable domains to enhance deliverability rates.

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