We are running a single Exchange 2010 server behind a TMG 2010 firewall.
A user is trying to use Mailchimp (an email marketing campaigns service) to send e-mails to external and internal recipients.
E-mails sent to internal users are not received as Exchange blocks e-mails that have sender addresses containing our own domain. The solution seems to be to setup an "IP Allow List Providers" on Exchange but I don't find a way of adding any
allowed IP addresses on EMC > Organisation Configuration > Hub Transport > IP Allow List Providers.
These are the IP addresses I am trying to add:
http://mailchimp.com/about/ips/
The only options seem to be Provider name & Lookup domain.
Can someone also explain what the lookup domain option is supposed to be?
Many thanks
Marco S