In our case, we had about 6500 corporate contacts who needed to be migrated.
There's a contacts screen in Office 365 which is accessible from the Admin portal. It's under users, then contacts.
Exporting from DominoIn IBM Notes, open your company's address book and press Ctrl+A on people. If you have your staff and non-staff in the same address book, you'll probably want to sort by company and deselect all the staff.
Next, click File, Export Contacts. You'll want to choose either "All contacts in this view" or "only the contacts you selected" depending upon your circumstances.
I'd recommend exporting all fields. It's a little messier but it means that you get your contacts address information (if you have it in Domino already).
Choose a place to save the file and make sure that you've used CSV.
Excel Stuff in the MiddleOpen the file in EXCEL,
Create a new file in excel with these fields as specified in this document.
You may have to create the Name column out of formula ... ie: Assuming that first name is in cell C2 and last name is in cell D2, you'd use =CONCATENATE(C2, " ", D2). Then Autofill the column and then copy and paste it into another blank column (so you could paste (special) as values.
Importing to Office 365The import to Office 365 is an entirely command line driven via PowerShell and these instructions helped enormously. Make sure that you connect to your exchange online service first. There's a link in step 1 but in case you can't find it, it's here.
I wish I could say that I completely understood the process I ran but I didn't.
It worked though, so I'm happy about that.
Now I just have to figure out groups.