Mail forwarding to a dynamic IP address.

[Martin G.H. Minkler]

Rajeev R Veedu schrieb:

> Since we have only an ADSL line on site office if there any way I could 
> forward the mails for these staff members to another Mail Server with 
> dynamic IP address?

Use a dyndns service [1] to make the remote ADSL IP resolvable by name 
and forward directly to that, then forward port 25 in Your firewall 
setup at the remote site to the mailserver inside the remote intranet 
(guessing at Your setup here).

e.g. have Your distributing mail server's virtual-maps state something 
like this

user at domain	user at dyndnsdomain

NB:
After automatic disconnects of the ADSL line until Your dyndns-client 
updates the IP You will get timeouts in Your logs but those are 
temporary and should be retried anyway.

To make things look nice You can create an explicit MX record for the 
dyndns domain. Remember to set the remote mailserver to accept mails 
addressed to the dyndns domain.

Even nicer: Use TLS between the two servers, maybe even with certs.


[1] https://www.dyndns.com/services/dns/dyndns/features.html

have fun

Martin