Hi Stuart A Wooding,

I would like to confirm the following information again.
1. Based on the first confirmation, do you mean that a user who has no less than four accounts, such as aaa@stuartwooding.com, bbb@stuartwooding.com, ccc@stuartwooding.com, ddd@stuartwooding.com?
2. Do the different accounts have different licenses in Office 365? For example, aaa@stuartwooding.com has only lync license, bbb@stuartwooding.com has only exchange license.

Moreover, please refer to the following steps to check the account licenses.
1. Login to Office 365 portal.
2. Choose the account, click Edit.
3. Check the licenses which the account has under the Assign licenses.
Please provide more detailed information about related account function in Office 365 for further research.

Thanks,
Ida Qiu

Hi Stuart A Wooding,

Based on the situation,there are two options that could resolve the issue,
1)Please wait for 30 days until the deleted login UPN's are permanently deleted from the Exchange recycle bin.But there is no guarantee that the accounts will delete.
2)Please use a PowerShell cmdlet to force the deletion of the recycle bin which was all going smoothly until the –RemoveFromRecycleBin parameter was not recognized.

For more information about installing PowerShell cmdlet,please refer to the following link.
http://onlinehelp.microsoft.com/en-US/Office365-enterprises/hh124998.aspx

Then, please do the following steps to connect to the server:
1. Open the Microsoft Online Services Module.
2. Run $cred=Get-Credential. When the cmdlet prompts you for credentials, type your Office 365 administration account credentials.
3. Run Connect-MsolService -Credential $cred. This cmdlet connects you to Office 365. Creating a context that connects you to Office 365 is required before running any of the additional cmdlets installed by the tool.
4. Run the Remove-MsolUser –UserPrincipalName <account id> -RemoveFromRecycleBin cmdlet to remove the soft deleted user.

Thanks,
Ida Qiu