# POP3 Service

The Post Office Protocol, version 3 (POP3) is a protocol that provides incoming e-mail storage and retrieval services. Determines how the security device evaluates POP3 traffic. The security device compares actual POP3 traffic with maximum settings of what you consider to be normal POP3 traffic. The security device considers any traffic exceeding such settings as anomalous.

To modify one or more of the following settings for POP3, enter a new value in the Current column for the parameter you want to adjust, and then click Apply:

Maximum Line Length: Specifies the maximum number of bytes for any POP3 line. Minimum: 1; maximum: 8192; default: 512.

Maximum Username Length: Specifies the maximum number of bytes in an POP3 user name. Minimum: 1; maximum: 8192; default: 64.

Maximum Password Length: Specifies the maximum number of bytes in a POP3 password. Minimum: 1; maximum: 8192; default: 64.

Maximum APOP Command Length: Specifies the maximum number of bytes for an Authenticated Post Office Protocol (APOP) command, which a POP3 user issues when authenticating himself to a POP3 mail server. Minimum: 1; maximum: 8192; default: 100.

Maximum Number of Messages: Specifies the maximum number of messages in a single mailbox on a POP3 server. Minimum: 100; maximum: 10,000,000; default: 10,000,000.

Maximum Number of Login Failures per Minute: Specifies the maximum number of failed login attempts per minute to a POP3 server from a single host. Minimum: 2; maximum: 100; default: 8.