Recommendation for changing settings

[Kevin Darcy]

Bruce Embrey wrote:

>Bind-Users:
> 
>
>I currently have my main mailserver for our domain configured with 4 ip
>addresses. I will be removing 2 of those addresses and wanted to find
>out the recommendation for how far in advance do I need to lower the TTL
>so that people won't have any problems getting to the server after the
>switchover?
>
Actually, it shouldn't really matter, since other mailservers will try 
all addresses and after a relatively-short delay, find the ones that 
still work. Theoretically, you could help this process along with 
"rrset-order", but given that email is a store-and-forward protocol, 
that seems like overkill...

If you were re-addressing your mailserver completely, my answer would be:

Depends on what your current TTL is set to. The most "polite" way to do 
this is to incrementally lower the TTL (e.g. cutting it by half each 
time) until you get down to a value that would represent an acceptable 
delivery delay.

                                                                         
                                          - Kevin