Unable to Invite new users to my organisation

[LabanNdungo]

Hi all.

Might anyone know of a reason why sending an invite to people who you would like to become users of your ArcGIS Online for Organizations account would fail? For some strange reason, when I invite users to my organizational account through the 'Invite Users to Organisation' button, they do not receive the invite. I have checked in their inboxes, junk and spam folders but the invite does not seem to arrive. My Organisation's page still lists the invited members as pending though. What might be the remedy for this situation? I would appreciate the help greatly.

[DanielStauning]

This issue might be due to your email server blocking the invitations. As a test, try sending an invitation to a personal email account rather than a work email account. If you recieve the invitation in your personal email, this is probably the issue and the work around is to add notifications@arcgis.com to your list of safe senders.