Re: [exim] switching mail servers

On Mon, 12 Nov 2007, Jonathan Addleman wrote:

> I will have to switch the DNS over ...

Not necessarily. If your MX records are pointing to an additional service
(virtual) IP address for Exim on your host, you could just shut down that
IP on the old host and bring it up on the other, when you are ready. No
DNS changes needed, and sending servers will defer while there is no Exim
listening on the IP.

> - First set a very low DNS TTL.

Otherwise, remember that you have to set the low TTL well in advance;
hosts won't get the new TTL until the old one that they got before you
made the change has timed out. So if your TTL is a week, then you should
probably change it over a week in advance.

Jethro.

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Jethro R Binks
Computing Officer, IT Services
University Of Strathclyde, Glasgow, UK