I sent out a campaign to a small number of subscribers which included 5 addresses (firstname.lastname@example.org) of staff within our company. However, none of them have received the campaign.
Do you know why this could be?
Do you know if you have any email filtering in place? If you do, the emails may have been marked as spam and have not been delivered. You may have to whitelist the campaign monitor servers. Details are here http://help.campaignmonitor.com/topic.aspx?t=77