SMTP Filters Variables

To set a variable, this function set is used:

When a predefined method is called, it usually sets one or more variables as its output and usually requires setting one or more variable as its input. Apart from the predefined variables, custom variables also exist and they can be used later in the code. To define a variable you just set its value:

The previous function defines a variable named aVariable and sets its value to aValue. 

A custom defined variable has lifetime that lasts until the end of a block. To preserve a variable across blocks and across contexts, the export function is used:

The lifetime of a filter with its contexts is per email message so the export function can be used to preserve the value of a variable specific to one email message through different stages of SMTP. For example, at the SMTP Outgoing context, the value of MailFromDomain is not set but can be, if in one of the SMTP Incoming events, an export(MailFromDomain) was made.

Within the SMTP Filter Language, the concept of variable expanding means that, within a string, a variable name may appear and at runtime the name will be replaced by the variable's value. In order for a variable to be expanded, its name must appear between "%" characters. An example of variable expanding is:

When you connect on the SMTP port, the greeting will be: "Hello. This is my AXIGEN server"

This expanding mechanism also works for comparing two variables: