Salesforce module provides you with the ability to select one from two "Message Queue" option.
Standard message queue
Standard message queue is based on Cron jobs. By default Salesforce cron generate schedules Every 1 minute.
For Cron installation refer to “Magento 2 CRON Setup“ article
How to enable Salesforce Standard Message Queue in Magento:
Go to Magento Admin panel - click Salesforce (on left side bar) - General Configuration - Advanced tab
2. Set "Message Queue" option to "Standard" and Save Config
Also you are able to change Salesforce cron time setting:
3. Go to Magento Admin panel - Stores - Configuration - Advanced - System - Cron configuration options for group:tnw_salesforce_crons tab
RabbitMQ message queue
RabbitMQ message queue is an open source message broker that offers a reliable, highly available, scalable, and portable messaging system. Message queues provide an asynchronous communications mechanism. It supplies faster data synchonization
For RabbitMQ installation refer to “RabbitMQ Overview“ Magento devdocs article
How to enable Salesforce RabbitMQ Message Queue in Magento:
Go to Magento Admin panel - click Salesforce (on left side bar) - General Configuration - Advanced tab
2. Set "Message Queue" option to "RabbitMQ" and Save Config