The original post here looks like it was actually a tech/email issue when inviting new people to come and play the game, but it's been causing a bit of confusion off and on for several years now.
Since it may well come up again the Sandycove friend request thread for in-game friends can be found here: forum.thesettlersonline.com/threads/17259-New-Players-Ask-for-friend-requests-here-Sandycove
Northisle is here: forum.thesettlersonline.com/threads/22483-New-Players-Ask-for-friend-requests-here-Northisle
And Newfoundland here: forum.thesettlersonline.com/threads/22481-New-Players-Ask-for-friend-requests-here-Newfoundland