On Mon, 14 Mar 2005, Marc Perkel wrote:
> If a transport fails it keeps retrying until the transport succeeds. Perhaps
> it might be handy to have an alternate transport so you can say - "if this
> transport fails - try this other transport".
Clarification: it is not the transport that keeps on retrying, it is
Exim that retries delivery of the message, and it re-runs the routers
each time.
Please read the FAQ. This item is carried over from Exim 3:
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(93) 04-May-1999 L fallback_transport
This would be a generic transport option, specifying a different transport to
be used if the first one failed. Failed hard, or failed soft? Or an option?
And if failed hard, is a bounce message sent as well, or not? There are uid
issues. Remote delivery would have to be done always in a subprocess so that
the main process could retain privilege in case the fallback transport was
local. That could be conditional. That's why this is labelled "Large". Some of
the things people want to do with this can be done by variations in the
routers, e.g. use $message_age to switch routers.
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I guess it isn't quite as large a project as it was, because remote
delivery in Exim 4 is already always done in a subprocess. However, you
*can* more or less simulate this by the use of another router that
switches on $message_age. Or even your normal router, with a suitable
expansion item for setting the transport.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
Get the Exim 4 book: http://www.uit.co.uk/exim-book
