Any question answered...

Yes. I can see that. However, there's the complication of it being a shared inbox. Which had been set up only for storing details, but not for sending mail. So I couldn't see it. Anyway.

Mapping custom fields, does it mean "map these fields to new user defined fields" or does it mean something else?

Thanks.

Preferably someone who's done it.

Export your existing contacts as a .csv file

Enter the new contact details in that csv file (which gives you all of the correct headers etc... and allows you to do any mapping / checking / weird functions in excel)

Import the new .csv file.