new ip address now email, rss feeds and backup not running

Ever since our ISP changed our IP address (servers also have new physical location in a new data centre) we have been having issues. I ran the ip address updater and got all website back on line OK. The problem appears to be DNS I think. Basically backup to S3, RSS feeds on websites and email (including daily backup email reports) has all stopped, seems to be when the server needs to get externalDNS addresses. I checked on the routing interface it has two entries but no gateway, thought this may be an issue too? can anyone shed any light on this for us.