pop3

Name

pop3 — Gromox POP3 server

Authentication

The POP3 server supports impersonation; see imap(8gx) for details.

Synopsis

pop3 [-c config]

Options

-c config

Read configuration directives from the given file. If this option is not specified, /etc/gromox/pop3.cfg will be read if it exists.

--version

Output version information and exit.

-?

Display option summary.

Configuration directives

The usual config file location is /etc/gromox/pop3.cfg.

block_interval_auths
The amount of time a user is blocked from connecting to the service after too many failed logins.
Default: 1 minute
config_file_path
Colon-separated list of directories in which further configuration files, especially those used by plugin instances, will be searched.
Default: /etc/gromox/pop3:/etc/gromox
context_average_mem

Default: 256K

context_average_units
Lower clamp is 256.
Default: 1024
context_max_mem

Default: 2M

context_num

Default: 200

data_file_path
Colon-separated list of directories in which static data files will be searched.
Default: /usr/share/gromox/pop3
enable_capa_implementation
When enabled, the server will include an "IMPLEMENTATION" line in the CAPA response (RFC 2449 §6.9). This is disabled by default, as it can facilitate potential attackers' information gathering.
Default: no
host_id
A unique identifier for this system. It is used in the POP3 protocol greeting lines (positive as well as negative). The identifier should only use characters allowed for hostnames.
Default: (system hostname)
pop3_auth_times
The number of login tries a user is allowed before the account is blocked.
Default: 3
pop3_certificate_passwd
The password to unlock TLS certificates.
Default: (unset)
pop3_certificate_path
Filesystem path to a certificate file for use with encrypted connection. The complete certificate chain should be present (as there is no other config directive to pull CA certs in).
Default: (unset)
pop3_cmd_debug
Log every incoming POP3 command and the return code of the operation in a minimal fashion to stderr. Level 1 emits commands that have failed execution, level 2 emits all commands.
Default: 0
pop3_conn_timeout
If a POP3 connection stalls for the given period, the connection is terminated.
Default: 3 minutes
pop3_force_tls
This flag controls whether clients must utilize TLS, either by way of implicit TLS (cf. pop3_listen_tls_port), or through the STLS command.
Default: false
pop3_listen_addr
AF_INET6 socket address to bind the POP3 service to.
Default: ::
pop3_listen_port
The TCP port to expose the POP3 protocol service on. (The IP address is fixed to the wildcard address.)
Default: 110
pop3_listen_tls_port
The TCP port to expose implicit-TLS POP3 protocol service (POP3S) on. (The IP address is fixed to the wildcard address.)
Default: (unset)
pop3_log_file
Target for log messages here. Special values: "-" (stderr/syslog depending on parent PID) or "syslog" are recognized.
Default: - (auto)
pop3_log_level
Maximum verbosity of logging. 1=crit, 2=error, 3=warn, 4=notice, 5=info, 6=debug.
Default: 4 (notice)
pop3_private_key_path
Filesystem path to the key file needed to unlock the TLS certificate.
Default: (unset)
pop3_support_tls
This flag controls the offering of TLS modes. This affects both the implicit TLS port as well as the advertisement of the STARTTLS extension and availability of the STLS command (RFC 2595) to clients.
Default: false
pop3_thread_charge_num
The maximum number of connections that each thread is allowed to process.
Default: 40
pop3_thread_init_num
The minimum number of client processing threads to keep around.
Default: 1
running_identity
An unprivileged user account to switch the process to after startup. To inhibit the switch, assign the empty value.
Default: gromox
state_path
Directory for runtime variadic data.
Default: /var/lib/gromox
tls_min_proto
The lowest TLS version to offer. Possible values are: tls1.0, tls1.1, tls1.2, and, if supported by the system, tls1.3.
Default: tls1.2

Files

  • data_file_path/pop3_code.txt: Mapping from internal POP3 error codes to textual descriptions.

  • /usr/lib/gromox/libgxs_*.so: service plugins

See also

gromox(7), midb_agent(4gx)