Recipient address rewriting modifies the email addresses of recipients in messages that enter your organization through the Barracuda Email Security Service (ESS). The primary reason for address rewriting on inbound messages is to deliver messages to the correct recipient. Instead of sending the message to the original envelope recipient, the address given with the RCPT TO by the sending mail server, the message is sent to the recipient where the alias domain is replaced by the primary domain.
A scenario of how you can use recipient address rewriting is during mergers and acquisitions to make the two organizations appear as one integrated organization. When Company A acquires Company B, Company A wants to consolidate email addresses across all its acquisitions to use the primary (Company A) mailbox. Recipient address rewriting will rewrite and route Company B's incoming emails to Company A's mailbox. For example, when user@b.com receives an email, ESS will rewrite the RCPT TO address to user@a.com and the intended recipient will receive the email.
To enable this feature, on the Domains page, click Edit in the Settings column for the domain you would like to enable address rewriting. Under Options, select Yes for Rewrite Recipients for Aliased Domains.