Although conversion processing is done using a regular IMTA channel program, under normal circumstances this channel is never specified directly either in an address or in an IMTA rewrite rule. IMTA controls access to the conversion channel via the CONVERSIONS mapping table in the IMTA mappings file (/etc/opt/SUNWmail/imta/mappings).
As IMTA processes each message it probes the CONVERSIONS mapping (if one is present) with a string of the form:
| |
|
IN-CHAN=source-channel;OUT-CHAN=destination-channel;CONVERT
|
|
source-channel is the channel from which the message is coming and destination-channel is the channel to which the message is heading. If the mapping produces a result, it should either be the string Yes or No. If Yes is produced, IMTA will divert the message from its regular destination to the conversion channel. If No is produced or if no match is found, the message will be queued to the regular destination channel.
For example, if all messages going to the tcp_intranet channel that do not originate from the tcp_intranet channel require conversion processing, the following mapping would then be appropriate:
| |
|
IN-CHAN=tcp_intranet;OUT-CHAN=tcp_intranet;CONVERT NO
|
| |
|
IN-CHAN=*;OUT-CHAN=tcp_intranet;CONVERT YES
|
|