For Universal Containers, which requires all email traffic to remain within its firewall and handles a high volume of cases with attachments, Email-to-Case is the recommended solution. Email-to-Case allows emails to be converted into cases within Salesforce while keeping email data secure within the company's firewall, accommodating the need for security and efficiency in handling customer cases.
Email-to-Case is the Salesforce standard for handling high-volume email processing securely. It allows for secure transmission via TLS encryption, and it can efficiently process large volumes (such as 2,000+ cases
/day) including multiple attachments.
Salesforce Email-to-Case offers the scalability, encryption, and attachment handling required for compliance with secure email policies. It also allows for configuration of attachment size limits and filtering.
A custom email service might offer flexibility but would be costlier to maintain and implement, and Einstein Activity Capture is intended for syncing email/calendar data, not for case creation or secure intake of customer email attachments.
Reference: Salesforce Help Documentation - Email-to-Case - Security and Attachment Management