Flexmail is a Belgian email marketing and CRM platform for SMEs and enterprises. It provides contact management, audience segmentation, campaign creation and sending, marketing automation, and performance analytics, with drag-and-drop design, segment-based targeting, and multi-step workflows. It tracks opens, clicks, bounces, and unsubscribes, and stores all data within the EU for GDPR compliance.
Power end-to-end data operations for your Flexmail API with Nexla. Our bi-directional Flexmail connector is purpose-built for Flexmail, making it simple to ingest data, sync it across systems, and deliver it anywhere — all with no coding required. Nexla turns API-sourced data into ready-to-use, reusable data products and makes it easy to send data to Flexmail or any other destination. With comprehensive monitoring, lineage tracking, and access controls, Nexla keeps your Flexmail workflows fast, secure, and fully governed.
Features
Type: API
SourceDestination
Seamless API Integration: Connect to any endpoint as source or destination without coding, with automatic data product creation
Visual Composition & Chaining: Build complex integrations using visual templates, chain API calls, and compose workflows with data validation and filtering
API Proxy: Expose curated slices of your data securely with a secure and customizable API proxy that validates and transforms data on the fly
Request optimization with intelligent batching, retry, and caching to minimize API calls and costs
Flexmail uses HTTP Basic Authentication, where your numeric Flexmail Account ID serves as the username and a Personal Access Token serves as the password. Before creating a credential in Nexla, you will need to locate your Account ID and generate a Personal Access Token from your Flexmail account settings.
Your Flexmail Account ID is a numeric identifier assigned to your Flexmail organization. It is used as the username in HTTP Basic Authentication requests to the Flexmail API.
Personal Access Tokens are the credentials used to authenticate API requests to Flexmail. Each token can be given a descriptive name so you can easily identify what it is used for.
Navigate to Settings > API > Personal access tokens.
Click Create new token.
Enter a descriptive name for the token (for example, "Nexla Integration") to help identify its purpose later.
Click Create (or the equivalent confirmation button) to generate the token.
Important
Copy the generated token immediately and store it in a secure location. Flexmail will not display the token value again after you navigate away from this page.
Keep the token value ready to enter when configuring the Nexla credential below.
For additional details on Flexmail API authentication and personal access tokens, refer to the Flexmail API documentation.
After selecting the data source/destination type, click the Add Credential tile to open the Add New Credential overlay.
Enter a name for the credential in the Credential Name field and a short, meaningful description in the Credential Description field.
Enter your numeric Flexmail Account ID in the Account ID field. This is the numeric identifier for your Flexmail organization, used as the HTTP Basic Auth username.
Enter your Flexmail Personal Access Token in the Personal Access Token field. This is the token generated under Settings > API > Personal access tokens in your Flexmail account, and it serves as the HTTP Basic Auth password. This field is treated as a secure/masked field.
Personal Access Tokens provide full API access to your Flexmail account. Store tokens securely and avoid sharing them. If a token is compromised, revoke it immediately in your Flexmail account settings and generate a new one.
Click the Save button at the bottom of the overlay. The newly added credential will now appear in a tile on the Authenticate screen during data source/destination creation.
Select the Flexmail connector tile from the list of available connectors, then select the credential that will be used to connect to the Flexmail instance, and click Next; or, create a new Flexmail credential for use in this flow.
Nexla provides pre-built templates that can be used to rapidly configure data sources to ingest data from common Flexmail endpoints. Select the endpoint from which this source will fetch data from the Endpoint pulldown menu. Available endpoint templates are listed in the expandable boxes below. Click on an endpoint to see more information about it and how to configure your data source for this endpoint.
List Webhook Events
This endpoint retrieves a complete list of all available webhook event types in Flexmail. Use this endpoint when you need to discover which events can trigger webhook notifications in your Flexmail account, such as contact subscriptions, unsubscribes, or campaign interactions.
This endpoint requires no additional parameters. Once selected, Nexla will automatically fetch all available webhook event types from the Flexmail API at https://api.flexmail.eu/webhook-events.
The results are useful for understanding which event types are available when registering webhooks using the Create Webhook destination endpoint.
This endpoint retrieves detailed information for a single Flexmail contact by their unique contact ID. Use this endpoint when you need to fetch the full profile of a specific contact, including their email address, custom fields, and subscription status.
Enter the unique numeric identifier of the contact you want to retrieve in the Id field.
Contact IDs can be found via the Flexmail application interface or by querying the Flexmail API directly.
This field is optional — if left blank, the endpoint URL will be incomplete and the request may fail. Ensure a valid contact ID is provided before testing.
This endpoint retrieves details for a single Flexmail interest category by its unique ID. In Flexmail, interests are topic groups or mailing lists that contacts can subscribe to, allowing marketers to segment their audience based on stated preferences.
Enter the unique numeric identifier of the interest you want to retrieve in the Id field.
Interest IDs can be found in your Flexmail account under the interests management section, or by querying the Flexmail API.
This field is optional — ensure a valid interest ID is entered before testing to receive accurate results.
This endpoint retrieves the details of a single Flexmail campaign by its unique campaign ID. Use this endpoint when you need to access configuration, content, or metadata for a specific email campaign, such as its subject line, sender details, or scheduled send time.
Enter the unique numeric identifier of the campaign you want to retrieve in the Id field.
Campaign IDs can be found in your Flexmail account under the campaigns section, or via the Flexmail API.
This field is optional — provide a valid campaign ID before testing to receive complete campaign details.
This endpoint retrieves details for a single Flexmail segment by its unique ID. Segments in Flexmail are filters on your contact database that define a specific group of contacts based on criteria such as language, interests, campaign behavior, or custom field values.
Enter the unique numeric identifier of the segment you want to retrieve in the Id field.
Segment IDs can be found in your Flexmail account under the segments management section.
This field is optional — provide a valid segment ID before testing to receive accurate segment details.
List contacts targeted by or interacted with a campaign
This endpoint retrieves the list of contacts associated with a specific campaign — including recipients, openers, clickers, and other interaction groups. Use this endpoint when you need to analyze which contacts were targeted by a campaign or how they interacted with it.
Enter the unique numeric identifier of the campaign in the Id field (Campaign ID).
This parameter is required. The campaign ID can be found in your Flexmail account under the campaigns section.
The response data is extracted from the $.data[*] path, meaning each contact record in the returned array will be treated as an individual record in Nexla.
This endpoint is useful for building audience lists for re-engagement campaigns or for analyzing campaign reach. For additional details, refer to the Flexmail API documentation.
Retrieve performance statistics for a campaign
This endpoint retrieves performance statistics for a specific Flexmail campaign, including opens, clicks, bounces, and unsubscribes. Use this endpoint when you need to analyze the effectiveness of a campaign and track key engagement metrics.
Enter the unique numeric identifier of the campaign in the Id field (Campaign ID).
This parameter is required. The campaign ID can be found in your Flexmail account under the campaigns section.
The response provides a single statistics object for the campaign, including aggregate counts for opens, clicks, bounces, and unsubscribes.
Campaign statistics are useful for reporting dashboards and performance analysis. For additional details, refer to the Flexmail API documentation.
List all segments
This endpoint retrieves a paginated list of all contact segments defined in your Flexmail account. Use this endpoint when you need an overview of all available segments, for example to populate a segment picker or to audit your current segmentation setup.
This endpoint requires no additional parameters. Once selected, Nexla will automatically fetch all segments from https://api.flexmail.eu/segments.
The response data is extracted from the $.data[*] path, meaning each segment record in the returned array is treated as an individual record in Nexla.
Once the selected endpoint template has been configured, click the Test button to the right of the endpoint selection menu to retrieve a sample of the data that will be fetched. Sample data will be displayed in the Endpoint Test Result panel on the right, allowing you to verify that the source is configured correctly before saving.
Flexmail data sources can also be manually configured to ingest data from any valid Flexmail API endpoint, including endpoints not covered by the pre-built templates, chained API calls, or custom request parameters. Select the Advanced tab at the top of the configuration screen, and follow the instructions in Connect to Any API to configure the API method, endpoint URL, date/time and lookup macros, path to data, metadata, and request headers.
All Flexmail REST API endpoints are hosted at https://api.flexmail.eu/. List endpoints typically return records under a data array, so the path to data is $.data[*]; single-object endpoints (such as Get a Contact or Get Campaign) use $ as the root path. For a complete list of available endpoints, refer to the Flexmail API documentation.
Once all of the relevant settings have been configured, click the Create button in the upper right corner of the screen to save and create the new Flexmail data source. Nexla will now begin ingesting data from the configured endpoint and will organize any data that it finds into one or more Nexsets.
Click the + icon on the Nexset that will be sent to the Flexmail destination, and select the Send to Destination option from the menu. Select the Flexmail connector from the list of available destination connectors, then select the credential that will be used to connect to the Flexmail organization, and click Next; or, create a new Flexmail credential for use in this flow.
Nexla provides pre-built templates that can be used to rapidly configure destinations to send data to common Flexmail endpoints. Select the endpoint to which data will be sent from the Endpoint pulldown menu. Then, click on the template in the list below to expand it, and follow the instructions to configure additional endpoint settings.
Create or update a contact
This endpoint creates a new contact or updates an existing contact in Flexmail, identified by their email address. Use this endpoint to synchronize contact data from external systems into Flexmail, keeping your contact database current.
This endpoint requires no additional path parameters. Nexla will send the Nexset record data as a JSON request body to https://api.flexmail.eu/contacts using the POST method.
Ensure the Nexset data includes at minimum an email address field, which Flexmail uses to identify whether to create a new contact or update an existing one. Additional fields may include:
first_name and last_name: The contact's name.
language: The preferred language of the contact (e.g., nl, fr, en).
custom fields: Any custom contact fields defined in your Flexmail account.
This endpoint updates specific fields of an existing Flexmail contact by their unique contact ID. Use this endpoint when you need to update contact attributes for known contacts without creating new records.
Enter the unique numeric identifier of the contact to be updated in the Id field. This is a path parameter that will be included in the request URL.
Nexla will send only the fields included in the Nexset record as a JSON PATCH request body. Only the fields provided will be updated; other contact fields will remain unchanged.
This endpoint permanently deletes a Flexmail contact by their unique contact ID. Use this endpoint when you need to remove contacts from Flexmail, for example as part of a data cleanup or compliance (right-to-erasure) workflow.
Enter the unique numeric identifier of the contact to be deleted in the Id field. This is a path parameter included in the request URL.
No request body is sent for DELETE operations.
:::warning Important
Deleting a contact is a permanent action and cannot be undone. Ensure that the correct contact ID is provided before activating this destination.
:::
Subscribe contact to interest
This endpoint subscribes a specific Flexmail contact to an interest area (topic group or mailing list). Use this endpoint to automatically assign contact interest subscriptions based on data from external systems, such as a CRM or website form submission.
Enter the unique numeric identifier of the contact in the Id field. This is a path parameter included in the request URL.
Ensure the Nexset data includes the interest ID to subscribe the contact to. The request body should include:
interest_id: The numeric ID of the interest the contact should be subscribed to. Interest IDs can be found in your Flexmail account under the interests management section.
This endpoint removes a Flexmail contact's subscription from a specific interest area. Use this endpoint to update interest preferences when a contact's opt-out or preference changes are captured in an external system.
Enter the unique numeric identifier of the contact in the Id field. This is the first path parameter included in the request URL.
Enter the unique numeric identifier of the interest from which the contact should be unsubscribed in the Interest Id field. This is the second path parameter in the request URL.
No request body is sent for this DELETE operation.
This endpoint unsubscribes a Flexmail contact from all mailings by their unique contact ID. Use this endpoint to process global unsubscribe requests received from external sources, ensuring the contact is no longer included in any Flexmail campaigns.
Enter the unique numeric identifier of the contact to unsubscribe in the Id field. This is a path parameter included in the request URL.
No request body is required for this operation.
:::warning Important
Unsubscribing a contact from all mailings is a significant action. The contact will no longer receive any email campaigns from your Flexmail account until they re-subscribe.
:::
Create Webhook
This endpoint registers a new webhook endpoint in Flexmail to receive event notifications. Use this endpoint to programmatically configure Flexmail to send event data (such as contact subscriptions, unsubscribes, or campaign interactions) to an external URL.
This endpoint requires no additional path parameters. Nexla will send the Nexset record data as a JSON request body to https://api.flexmail.eu/webhooks.
Ensure the Nexset data includes the required fields for registering a webhook, which typically include:
url: The target URL that will receive the webhook notifications.
events: An array of event type names that should trigger the webhook. Use the List Webhook Events source endpoint to discover available event types.
This endpoint deletes an existing Flexmail webhook subscription by its unique webhook ID. Use this endpoint to programmatically remove webhook registrations that are no longer needed.
Enter the unique numeric identifier of the webhook to be deleted in the Id field. This is a path parameter included in the request URL.
No request body is sent for this DELETE operation.
This endpoint creates a new email campaign in Flexmail. Use this endpoint to programmatically create campaigns based on data-driven inputs, such as generating personalized campaigns from a CRM or automation system.
This endpoint requires no additional path parameters. Nexla will send the Nexset record data as a JSON request body to https://api.flexmail.eu/campaigns.
Ensure the Nexset data includes the required fields for campaign creation, such as the campaign name, subject, sender details, and content configuration, as specified in the Flexmail API documentation.
This endpoint triggers the sending or scheduling of an existing Flexmail campaign by its campaign ID. Use this endpoint to programmatically dispatch campaigns at a specific time or immediately after they are created.
Enter the unique numeric identifier of the campaign to send in the Id field (Campaign ID). This parameter is required.
Ensure the Nexset data includes the required fields for sending the campaign. Depending on your Flexmail configuration, this may include:
scheduled_at: The date and time to schedule the campaign (ISO 8601 format). If omitted, the campaign may be sent immediately.
segments or interests: The target audience identifiers for the campaign.
This endpoint updates the content, subject line, or settings of an existing Flexmail campaign by its campaign ID. Use this endpoint when you need to make programmatic changes to campaigns before they are sent.
Enter the unique numeric identifier of the campaign to update in the Id field (Campaign ID). This parameter is required.
Nexla will send only the fields included in the Nexset record as a JSON PATCH request body. Only the provided fields will be updated; all other campaign settings will remain unchanged.
This endpoint permanently deletes a Flexmail campaign by its unique campaign ID. Use this endpoint to remove campaigns that are no longer needed or were created in error.
Enter the unique numeric identifier of the campaign to delete in the Id field (Campaign ID). This parameter is required.
No request body is required for this DELETE operation.
:::warning Important
Deleting a campaign is a permanent action and cannot be undone. Ensure that the correct campaign ID is provided before activating this destination.
:::
Send a test campaign
This endpoint sends a test or preview version of a Flexmail campaign to a specified test email address. Use this endpoint to validate campaign content and rendering before sending to the full audience.
Enter the unique numeric identifier of the campaign to test in the Id field (Campaign ID). This parameter is required.
Ensure the Nexset data includes the test recipient email address or addresses in the request body, as required by the Flexmail API.
This endpoint creates a new contact segment in Flexmail. Segments are filters on your contact database that define a specific group of contacts based on criteria such as interests, language, or campaign behavior. Use this endpoint to programmatically create segments based on external data logic.
This endpoint requires no additional path parameters. Nexla will send the Nexset record data as a JSON request body to https://api.flexmail.eu/segments.
Ensure the Nexset data includes the required fields for segment creation, such as the segment name and any filter criteria, as specified in the Flexmail API documentation.
This endpoint updates the criteria or name of an existing Flexmail segment by its unique segment ID. Use this endpoint to programmatically modify segment definitions based on updated business rules or data criteria.
Enter the unique numeric identifier of the segment to update in the Id field (Segment ID). This parameter is required.
Nexla will send only the fields included in the Nexset record as a JSON PATCH request body. Only the provided fields will be updated; all other segment settings will remain unchanged.
This endpoint permanently deletes a Flexmail segment by its unique segment ID. Use this endpoint to remove segments that are no longer needed as part of a data management or cleanup workflow.
Enter the unique numeric identifier of the segment to delete in the Id field (Segment ID). This parameter is required.
No request body is required for this DELETE operation.
:::warning Important
Deleting a segment is a permanent action and cannot be undone. Ensure that the correct segment ID is provided before activating this destination.
:::
Create a new interest
This endpoint creates a new interest (mailing list or topic group) in Flexmail. Interests allow contacts to self-select their preferences, helping marketers segment audiences based on stated interests. Use this endpoint to programmatically create new interest categories.
This endpoint requires no additional path parameters. Nexla will send the Nexset record data as a JSON request body to https://api.flexmail.eu/interests.
Ensure the Nexset data includes the required fields for interest creation, such as the interest name, as specified in the Flexmail API documentation.
This endpoint updates an existing Flexmail interest by its unique interest ID. Use this endpoint to programmatically rename or modify interest definitions in your Flexmail account.
Enter the unique numeric identifier of the interest to update in the Id field (Interest ID). This parameter is required.
Nexla will send only the fields included in the Nexset record as a JSON PATCH request body. Only the provided fields will be updated; all other interest settings will remain unchanged.
This endpoint permanently deletes a Flexmail interest by its unique interest ID. Use this endpoint to remove interest categories that are no longer needed.
Enter the unique numeric identifier of the interest to delete in the Id field (Interest ID). This parameter is required.
No request body is required for this DELETE operation.
:::warning Important
Deleting an interest is a permanent action and cannot be undone. Contacts subscribed to this interest will lose their subscription when the interest is deleted.
:::
Create a new custom contact field
This endpoint creates a new custom contact field definition in Flexmail. Custom fields allow you to store additional contact attributes beyond the standard fields provided by Flexmail. Use this endpoint to programmatically extend your Flexmail contact schema based on external data requirements.
This endpoint requires no additional path parameters. Nexla will send the Nexset record data as a JSON request body to https://api.flexmail.eu/custom-fields.
Ensure the Nexset data includes the required fields for custom field creation, such as the field name and data type, as specified in the Flexmail API documentation.
This endpoint updates an existing custom contact field definition in Flexmail by its unique field ID. Use this endpoint to programmatically rename or modify custom field definitions in your Flexmail account.
Enter the unique numeric identifier of the custom field to update in the Id field (Custom field ID). This parameter is required.
Nexla will send only the fields included in the Nexset record as a JSON PATCH request body. Only the provided fields will be updated.
This endpoint permanently deletes a custom contact field definition from Flexmail by its unique field ID. Use this endpoint to remove custom fields that are no longer needed.
Enter the unique numeric identifier of the custom field to delete in the Id field (Custom field ID). This parameter is required.
No request body is required for this DELETE operation.
:::warning Important
Deleting a custom field is a permanent action and cannot be undone. All contact data stored in this field will also be removed.
:::
Flexmail destinations can also be manually configured to send data to any valid Flexmail API endpoint. Select the Advanced tab at the top of the configuration screen, and follow the instructions in Connect to Any API to configure the API method, data format, endpoint URL, request headers, attribute exclusions, record batching, and response webhooks.
The Flexmail REST API accepts data in application/json format for all destination operations. All endpoints are hosted at https://api.flexmail.eu/; for update or delete operations, include the ID of the object to be modified at the end of the URL. Nexla can also be configured to send the response received from the Flexmail API after each call to a new Nexla webhook data source. For a complete list of available endpoints, refer to the Flexmail API documentation.
Once all endpoint settings have been configured, click the Done button in the upper right corner of the screen to save and create the destination. To send the data to the configured Flexmail endpoint, open the destination resource menu, and select Activate.
The Nexset data will not be sent to Flexmail until the destination is activated. Destinations can be activated immediately or at a later time, providing full control over data movement.
