I'm trying to setup DKIM for my domain as per the instructions in the control panel.  I've set up a selector called "admin" which I hope will cover all my users' emails.  I've then set up the TXT record in my DNS manager for the domain but it won't verify.

Can anyone see what I'm missing to make this work or does it just take some time to establish itself across the servers and will be fine in a couple of days?

Thanks for all you help in advance.

Rob