7.3. HELO

This script is executed on HELO and EHLO. It allows verification of identification.

7.3.1. Variables

These are the pre-defined variables available.

Variable	Type	Read-only	Description
$arguments	array	yes	Context/hook arguments
$connection	array	yes	Connection/session bound
$transaction	array	yes	Transaction bound
$context	any	no	Connection bound user-defined (default none)

7.3.1.1. Arguments

Array item	Type	Example	Description
verb	string	“EHLO”	HELO or EHLO command
host	string	“mail.example.com”	HELO hostname of sender
extensions	array	[“PIPELINING”, “SIZE 1…	The extensions to be sent to the client (if EHLO was issued)

7.3.1.2. Connection

Array item	Type	Example	Description
id	string	“18c190a3-93f-47d7-bd…”	ID of the connection
remoteip	string	“192.168.1.11”	IP address of the connected client
remoteport	number	41666	TCP port of connected client
remoteptr	string	“mail.example.org”	Reverse DNS (FCrDNS) for remoteip (not always available)
remoteuid	number	106	UNIX socket remote user id (not always available)
localip	string	“10.0.0.1”	IP address of the server
localport	number	25	TCP port of the server
serverid	string	“inbound”	ID of the server
tls	array		TLS information (if TLS was started)
auth	array		AUTH information (not always available)

7.3.1.2.1. TLS

Array item	Type	Example	Description
protocol	string	“TLSv1.3”	The protocol
cipher	string	“ECDHE-RSA-AES256-SHA384”	The cipher
keysize	number	256	The keysize
sni	string	“example.com”	The SNI hostname (not always available)
peercert	array		The peer certificate (if provided by the client)

7.3.1.2.1.1. Peercert

Array item	Type	Example	Description
x509	X509Resource		An X509Resource to be used with the X509 class
error	number	18	The peer certificate validation error (see OpenSSLs SSL_get_verify_result(3))

7.3.1.2.2. AUTH

Array item	Type	Example	Description
mechanism	string	“PLAIN”	SASL mechanism (always in uppercase)
username	string	“mailuser”	SASL username (not always available)

7.3.1.3. Transaction

Array item	Type	Example	Description
id	string	“18c190a3-93f-47d7-bd…”	ID of the transaction

7.3.2. Functions

helo.Accept([options])

Accept the HELO or EHLO command. Optionally change the host of the sending client, which is written back to the $connection variable.

Parameters

options (array) – an options array

Returns

doesn’t return, script is terminated

The following options are available in the options array.

• extensions (array) SMTP service extensions to announce in EHLO responses.

• host (string) Change the client HELO hostname for the current connection.

• reason (string) First line of the response. The default is the servers hostname.

• reply_codes (array) The array may contain code (number) and enhanced (array of three numbers). The default code is 250 and enhanced is not used.

helo.Reject([reason[, options]])

Reject the HELO or EHLO command with a permanent (554) error.

Parameters

• reason (string or array) – reject message with reason

• options (array) – an options array

Returns

doesn’t return, script is terminated

The following options are available in the options array.

• disconnect (boolean) Disconnect the client. The default is false.

• reply_codes (array) The array may contain code (number) and enhanced (array of three numbers). The default code is 554 and enhanced is not used.

helo.Defer([reason[, options]])

Defer the HELO or EHLO command with a temporary (450) error.

Parameters

• reason (string or array) – defer message with reason

• options (array) – an options array

Returns

doesn’t return, script is terminated

The following options are available in the options array.

• disconnect (boolean) Disconnect the client. The default is false.

• reply_codes (array) The array may contain code (number) and enhanced (array of three numbers). The default code is 450 and enhanced is not used.

7.3.3. On script error

On script error Defer() is called.

7.3.4. On implicit termination

If not explicitly terminated then Accept() is called.