have 4 MX record:
MX 3 that is the main server where people retrieve their mail in
location A
MX 5 that is another machine, phisically adjacent to the first one,
that is there just to allow me to do shgort maintenance stops on
main server and then forche the secondary to immediately feed the
primary.
MX 10 is a third machine, out of my control, that is on site B.
MX 20 is a fourth site, C , again out of my control.
The topology is that site A and C are connected to site B trought
2MB lines, and site B is connected to the internet via a single T3
line.
The problem arise when there is a break on one of these
connection, so the message remain at their originate points (the
problem is quite severe when the connection down is the one
between B and the internet, althought the most frequent failore is
between A and B ).
I thought of replacing the MX 20 server with another one, on a
friendly site, with a completely different connection to the net, to
which i can connect via dialup. (as i can do with B) .
Is there an easy way so , after i detect a link failure for more then
20' i can setup a dialup connection to D (the new MX20 server) and
from there force the delivery of pending e-mail (of course via this
way i can also retrieve B, since it is unlikely both A-B and B-D
connection are down at the same time - unless is B itself down, of
course !)
Leonardo Boselli
nucleo informatico e telematico
Dipartimento Ingegneria Civile
Universita` di Firenze
V. S. Marta 3 - I-50139 Firenze
tel +39()0554796431 fax +39()055495333
http://www.dicea.unifi.it/~leo
