Skip to content


Repository files navigation


Copyright (C) 2018-2023 The Open Library Foundation

This software is distributed under the terms of the Apache License, Version 2.0. See the file "LICENSE" for more information.


mod-email provides an API for delivering email messages.


For email delivery mod-email relies on the external SMTP server, configuration for which is stored by mod-email in its own database. The module also provides CRUD API for managing it. If mod-email couldn't find SMTP configuration in its own DB, it'll try to fetch one frommod-configuration, copy it to the DB and then delete it from mod-configuration.

Supported configuration parameters

mod-email parameter mod-configuration parameter DESCRIPTION EXAMPLES
host EMAIL_SMTP_HOST the hostname of the smtp server 'localhost'
port EMAIL_SMTP_PORT the port of the smtp server 502
loginOption EMAIL_SMTP_LOGIN_OPTION the login mode for the connection DISABLED, OPTIONAL or REQUIRED
trustAll EMAIL_TRUST_ALL trust all certificates on ssl connect true or false
ssl EMAIL_SMTP_SSL sslOnConnect mode for the connection true or false
startTlsOptions EMAIL_START_TLS_OPTIONS TLS security mode for the connection DISABLED, OPTIONAL or REQUIRED
username EMAIL_USERNAME the username for the login 'login'
password EMAIL_PASSWORD the password for the login 'password'
from EMAIL_FROM 'from' property of the email
authMethods AUTH_METHODS authentication methods 'CRAM-MD5 LOGIN PLAIN'
expirationHours Messages which are older than expiration hours are considered as expired and gets deleted. Default value will be 24 hours 12

Configuration using mod-email's API

This method of configuration is preferred.

Required configuration parameters:

  • Host
  • Port
  • User name
  • Password

SMTP configuration (GET /smtp-configuration/{id}) example:

    "id": "d2db040b-3247-4b2b-8db4-5ef449e092ad",
    "host": "",
    "port": 587,
    "username": "example-username",
    "password": "example-password",
    "ssl": false,
    "trustAll": false,
    "loginOption": "NONE",
    "startTlsOptions": "OPTIONAL",
    "authMethods": "",
    "from": "",
    "emailHeaders": [
            "name": "Reply-To",
            "value": ""

Use GET /smtp-configuration to get all configurations. It's forbidden to create more than one configuration, but this call helps to find the ID of the configuration entry to use it in GET, PUT, DELETE requests.

Configuration using mod-configuration (deprecated)

This method of configuration is deprecated and needs to be avoided.

All SMTP configuration entries need their module field to be set to SMTP_SERVER.

Module configuration example:

curl -X POST \
 http://localhost:9130/configurations/entries \
 -H 'Content-Type: application/json' \
 -H 'X-Okapi-Tenant: <tenant>' \
 -H 'x-okapi-token: <token>' \
     "module": "SMTP_SERVER",
     "configName": "smtp",
     "code": "EMAIL_SMTP_HOST",
     "description": "server smtp host",
     "default": true,
     "enabled": true,
     "value": ""

The example of request body with authentication methods configuration:

    "module": "SMTP_SERVER",
    "configName": "smtp",
    "code": "AUTH_METHODS",
    "description": "Authentication methods",
    "default": true,
    "enabled": true,
    "value": "CRAM-MD5 LOGIN PLAIN"


Module provides next API:

POST /email Push email to mod-email for sending message to recipient
GET /smtp-configuration Get all SMTP configurations
GET /smtp-configuration/{id} Get SMTP configuration
POST /smtp-configuration/{id} Post SMTP configuration
PUT /smtp-configuration/{id} Put SMTP configuration
DELETE /smtp-configuration/{id} Delete SMTP configuration


   mvn install

See that it says "BUILD SUCCESS" near the end.


When running the jar file the module looks for the http.port and port system property variables in this order, and uses the default 8081 as fallback. Example:

java -Dhttp.port=8008 -jar target/mod-email-fat.jar

The Docker container exposes port 8081.


Build the docker container with:

  • docker build -t mod-email .

Test that it runs with:

  • docker run -t -i -p 8081:8081 mod-email

Installing the module

Follow the guide of Deploying Modules sections of the Okapi Guide and Reference, which describe the process in detail.

First of all you need a running Okapi instance. (Note that specifying an explicit 'okapiurl' might be needed.)

   cd .../okapi
   java -jar okapi-core/target/okapi-core-fat.jar dev

We need to declare the module to Okapi:

curl -w '\n' -X POST -D -   \
   -H "Content-type: application/json"   \
   -d @target/ModuleDescriptor.json \

That ModuleDescriptor tells Okapi what the module is called, what services it provides, and how to deploy it.

Deploying the module

Next we need to deploy the module. There is a deployment descriptor in target/DeploymentDescriptor.json. It tells Okapi to start the module on 'localhost'.

Deploy it via Okapi discovery:

curl -w '\n' -D - -s \
  -X POST \
  -H "Content-type: application/json" \
  -d @target/DeploymentDescriptor.json  \

Then we need to enable the module for the tenant:

curl -w '\n' -X POST -D -   \
    -H "Content-type: application/json"   \
    -d @target/TenantModuleDescriptor.json \

Additional information

Issue tracker

See project MODEMAIL at the FOLIO issue tracker.


See the built target/ModuleDescriptor.json for the interfaces that this module requires and provides, the permissions, and the additional module metadata.

API documentation

This module's API documentation.

Code analysis

SonarQube analysis.

Download and configuration

The built artifacts for this module are available. See configuration for repository access, and the Docker image.