What are the three default methods available in Recipient Verification to verify that a recipient mailbox exists? Pick the 3 correct responses below.

The Proofpoint Protection Server (PPS) uses three primary, default methods for Recipient Verification to determine if a recipient mailbox is valid before accepting a message. These methods are:

1. SMTP verification: The system queries the downstream mail server using SMTP commands (like RCPT TO) to see if the server accepts the address.

2. LDAP verification: PPS queries a configured LDAP directory, such as Active Directory, to confirm the recipient's email address exists.

3. User Repository verification: The system checks against its own internal database of known users, which can be populated through various means, including LDAP synchronization or manual import.

A. Email the recipient: This is not an automated verification method; it is inefficient and would generate unnecessary email traffic or backscatter.

E. CSV File verification: A CSV file is a data source used to populate the User Repository, not a direct, real-time verification method itself.

F. DNS verification: DNS is used to resolve a domain's MX records to find the mail server, but it cannot verify if a specific mailbox exists.

1. Proofpoint Protection Server 8.18 Administrator Guide. Chapter: System > Recipient Verification. pp. 215-218. This section details the configuration options for recipient validation

explicitly outlining SMTP Call-Ahead (Dynamic Verification)

LDAP lookups

and checking against the internal Proofpoint User Repository as the primary methods.

2. Proofpoint Knowledge Base Article #10072. "Configuring Recipient Verification Methods in PPS." This article provides a step-by-step guide for administrators

describing the setup and use cases for the three core verification types: SMTP

LDAP

and the local User Repository. It clarifies that these are the built-in mechanisms for validating inbound recipients.