On some occasions email recipients will report that messages are not arriving at their inbox.  The messages that they do not receive can be of any type, Email Campaign, Coaching Email, Autoresponders or Notifications (such as event reminders).  If a specific group of senders that are receiving at the same domain (such as a speciifc company) report the same issue, the IT department can whitelist the outbound messages from Luminate Online to ensure that these messages reach their inbox.

The current list of IP ranges that Luminate Online uses for outbound mail are:

66.45.103.0/25
69.48.252.128/25
209.163.168.192/26
64.244.120.32/27
64.244.122.192/27
64.244.127.128/27
64.244.127.160/27

Luminate Online attaches the domain outboundmail.convio.net to the outbound IP addresses that are used. If you have the option to whitelist a sender domain, whitelisting outboundmail.convio.net will allow the delivery. 

Note, these IPs are in CIDR notation.  For information on CIDR, see this wikipedia page.