Email Listener synchronization service
To keep your team's emails available inside Creatio without manual imports, Creatio connects to MS Exchange and IMAP/SMTP mail services automatically. The Email Listener synchronization service handles this connection by subscribing to new message events in your mailboxes and delivering emails to Creatio in real time. Working with mail services without this microservice is not supported.
Service components
The Email Listener components are listed in the table below.
Component | Description |
|---|---|
Email Listener primary module | Connects to mailboxes using their credentials and creates subscriptions to new message events. Keeps subscriptions open in memory to detect and load incoming emails quickly. |
Email Listener secondary module | Downloads emails from the mail server and delivers them to Creatio. Offloading downloads to this module reduces the load on the primary module, which stays available for managing subscriptions and sending emails. This separation is especially useful during peak mail flows. |
NoSQL Redis DBMS | Stores the list of served mailboxes. Because this information is centralized, any container can respond to Creatio requests — adding a new subscription or checking an existing one — without depending on the specific node that created it. Requires authorized access from the Email Listener service and a dedicated database. |
RabbitMQ | Distributes processing tasks between service components in high-load environments. Keeps the service fault-tolerant and scalable as mailbox volume grows. Since version 8.3.4, you can improve message processing reliability and fault tolerance in the cloud and in distributed environments by configuring RabbitMQ quorum queues in the Email Listener microservice. |
The workflow of the Email Listener synchronization service is available in the figure below.
Scalability
As the number of active mailboxes grows, you can add processing nodes to keep the service responsive without restarting it. Out of the box, one handler instance serves up to 50 active mailboxes. You control the number of instances with the replicaCount parameter, and you can also configure automatic scaling based on the number of active subscriptions. Nodes run as StatefulSet instances in Kubernetes.
Compatibility with Creatio products
The Email Listener synchronization service version 2.0 (IMAP/SMTP support) is compatible with all Creatio products of version 7.16 and later.
The Email Listener synchronization service version 1.0 (MS Exchange support) is compatible with all Creatio products of version 7.15.2 and later.
Installation options
Use Kubernetes with the Helm package manager for production deployments — this provides the reliability and scaling capabilities the service needs in live environments. For development and testing, Docker offers a faster setup path. An in-memory repository is sufficient for development deployments. Learn more about deploying the synchronization service: Deploy the synchronization service via Kubernetes (user documentation), Deploy the synchronization service in Docker (user documentation).
See also
Email Listener synchronization service (user documentation)