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I am moving servers, both of them running Debian (oldstable and stable). Both are running Exim4. When I switch the DNS entries over to the new server, I'd like the old server to still forward incoming mail to my new server for processing, so that users do not see any outage. How can I do this?

Arne
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2 Answers2

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Just replace all routers by one manualroute that points directly to the new MX:

begin routers
redir:
  driver = manualroute
  domains = *
  transport = remote_smtp
  route_list = * 12.34.56.78

Here 12.34.56.78 - is an IP-address of your new MX where all messages should go.

Kondybas
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  • Seems like one way to do this. Thanks. One comment: Since I am dealing with Debian, maybe it's enough if I set the dc_smarthost variable in the update-exim4.conf.conf? Can anyone comment on that? – Arne Jan 02 '14 at 18:26
  • Tried the dc_smarthost, and no, it does not suffice. – Arne Jan 09 '14 at 17:10
  • Tested your router now, it works great. – Arne Jan 09 '14 at 19:05
2

You can use the .forward files and/or redirection mechanisms as documented and illustrated here.

An example of the forward file from the above link is:

Sam.Reman, [email protected]
Ketan Maheshwari
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