Channel options

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Channel options are available to adjust many attributes and aspects of channel operation. Unified Configuration channel options subsume the channel keywords of legacy configuration, as well as the second and optional additional lines of legacy configuration channel definitions; and the Unified Configuration options group allows setting the channel-specific options of legacy configuration (those set in legacy configuration in a channel option file). That is, in legacy configuration, channel keywords would appear after the channel name on the first line of the channel definition in imta.cnf, and then the second and optional additional lines of a channel definition in imta.cnf would set the official_host_name for a channel and optionally the local_host_alias and additional_host_names; while channel-specific options would be set in the channel-name_option channel option file.

In Unified Configuration, any desired channel options are set under a named channel group; e.g., for options that merely need to be turned on:

msconfig> set channel:channel-name.option-name

or for channel options that take an argument:

msconfig> set channel:channel-name.option-name option-value

Some channel options take arguments; each option argument is limited in general to 40 characters, though some special options allow arguments of 256 characters (252 characters in iMS 5.2 and earlier), and a few options (as of 7.0.5 including sourcefilter and destinationfilter) allow arguments up to 1024 characters.

In Unified Configuration, option argument case is preserved even if not quoted. Quoting is not necessary for most option arguments; but options that take multiple "arguments" (in legacy configuration terms), must in Unified Configuration be set by specifying a single, quoted argument. For instance:

msconfig> set channel:tcp_local.saslswitchchannel tcp_auth = tcp_auth
msconfig# set channel:tcp_local.backoff "PT30M PT1H PT1H PT2H PT4H PT8H" = PT30M PT1H PT1H PT2H PT4H PT8H

In legacy configuration, option arguments are normally forced to lowercase, but case will be preserved if the option argument is quoted. Also, while legacy configuration options are normally limited to taking at most five arguments, when the arguments themselves are quoted that restriction is lifted; (see for instance, the backoff channel option).

Note that the channel-specific options -- those set in legacy configuration in channel option files, rather than as legacy configuration channel keywords -- in Unified Configuration are set under the options group, e.g.,

msconfig> set channel:tcp_local.options.ALLOW_ETRNS_PER_SESSION 2

Since channel-specific options are specific to the type of channel in question -- different types of channels tend to have completely different channel-specific options -- look under the discussions of the specific channel types to find out details of what channel-specific options are available, as channel-specific options do not appear under the general list of options, nor as channel options.

See also: