7.9 Call-out Configuration

Mailfromd Conf: ehlo-domain string

Sets default domain used in ‘EHLO’ (or ‘HELO’) SMTP command when probing the remote host. This value can be overridden by ‘from’ parameter to poll command (see poll).

This statement assigns the value string to the ‘ehlo_domain’ variable (see ehlo_domain), and is therefore equivalent to

setvar ehlo_domain string;

Mailfromd Conf: mail-from-address string

Sets default email addresses used in ‘MAIL FROM:’ SMTP command when probing the remote host. This value can be overridden by ‘as’ parameter to poll command (see poll).

This statement assigns the value string to the ‘mailfrom_address’ variable (see mailfrom_address), and is therefore equivalent to

setvar mailfrom_address string;

Mailfromd Conf: enable-vrfy bool

Enables the use of SMTP VRFY statement prior to normal callout sequence. If VRFY is supported by the remote server, mailfromd relies on its reply and does not perform normal callout.

The use of this statement is not recommended, because many existing VRFY implementations always return affirmative result, no matter is the requested email handled by the server or not.

The default is enable-vrfy no, i.e. VRFY is disabled.

Mailfromd Conf: smtp-starttls string

Configures whether to issue the STARTTLS command if the mail server offers such capability. Allowed values are:

smtp-starttls value: never

Never use STARTTLS.

smtp-starttls value: always

Always use STARTTLS if supported by the server.

smtp-starttls value: ondemand

Use STARTTLS only if MAIL FROM: command failed with the code 530 (Authorization required).

Default is ‘ondemand’.

Notice, that the smtp-starttls feature depends on whether GnuTLS support is available in libmailutils. You can check whether it is available by inspecting the output of mailfromd --show-defaults (see Examining Defaults): if so, the ‘optional features’ line will contain the word ‘STARTTLS’.

Mailfromd Conf: tls { ... }

Configures TLS settings for the callout. This is a compound statement. The two most important statements in this compound are:

Mailfromd TLS: ssl-priorities string

Configures the TLS session’s handshake algorithms and options in a compact, easy-to-use format. See Priority strings in GnuTLS, for a detailed description of the priority string format.

Default value is ‘NORMAL:%COMPAT’. You may need to adjust it in order to work with older or misconfigured servers, e.g.:

tls {
  ssl-priorities "LEGACY:%COMPAT";
}

Mailfromd TLS: handshake-timeout n

Sets the timeout for TLS handshake to n seconds.

The remaining three statements are not of much importance for callout. They are described here for completeness sake:

Mailfromd TLS: ssl-ca-file file

Specifies the pathname of the certificate authority file.

Mailfromd TLS: ssl-certificate-file file

Specifies the pathname of the certificate file.

Mailfromd TLS: ssl-key-file file

Specifies the pathname of the certificate key file.