ISP changed, several issues

Hi there,

I have some Problems with our ASG 220 since we changed our ISP yesterday.

Before we had a had a sysmetric line with one static IP address, now we have VDSL with 5 usable static IP addresses.

The first problem is: I changed the WAN Interface from ethernet to DSL with PPPoE. This does not work, when it is plugged to eth1 (as it is recommended) but it works when I plug it to eth5.

The second problem is:
with the old ISP we had a DNS record for our single static IP address that pointed mail.mydomain.com to the single static IP address we had.

With our new ISP we have a static IP address ***.***.***.49 for our router, (the ASG) plus the range ***.***.***.50 - 54, which is usable for other services like Mail.

Now we have a new DNS record that points mail.mydomain.com to the IP address ***.***.***.50.
That was apparently a mistake, we should have used ***.***.***.49, because now neither SSL vpn is working (I found a workarround for this...) nor is the user portal available under mail.mydomain.com nor, and this is worse, it does not accept external mail.

Today no one is available at our ISP to change the DNS record, so my question is, can I redirect incoming traffic for ***.***.***.50 to the WAN interface?

Any help is very much appreciated.

Thanks in advance,
Matthias