12.4.3.9 Source Channel Switching Based on User or Domain Settings

Keywords: userswitchchannel. See also switchchannel on 12.4.3.8 Alternate Channels for Incoming Mail (Switch Channels)

Source channel switching based on user or domain settings is now possible. There are three new settings involved:

1. A new channel keyword userswitchchannel. This keyword must be present on the initial source channel for user channel switching to occur.

2. A new MTA option LDAP_DOMAIN_ATTR_SOURCE_CHANNEL that specifies the name of a domain-level attribute containing the name of the channel to which to switch.

3. A new MTA option LDAP_SOURCE_CHANNEL that specifies the name of a user-level attribute containing the name of the channel to which to switch.

Additionally, the channel being switched to must be set to allow channel switches. That is, it cannot be marked with the noswitchchannel keyword. Switching is done based on information returned by rewriting the MAIL FROM address. Note that MAIL FROM addresses are easily forged so this functionality should be used with extreme care.