Hi Simon, welcome to Microsoft Q&A.
I'm sorry to hear about your loss. If you want to request access to the data or content of a deceased family member's account, you will need to follow a formal legal process, instead of sending emails or contacting support directly in most regions.
In general, in most places, all things you need to do is obtain a valid non-criminal subpoena or court order and serve it on Microsoft’s Registered Agent in your specific state or region. Note that you should look up the registered agent's address through your local Secretary of State’s website (for example, in many US states, this is handled by CSC - Lawyers Incorporating Service) rather than sending it to Microsoft's headquarters in Redmond.
Especially, if you are in:
- Europe: Microsoft will respond to non-criminal subpoenas and court orders served on Microsoft Ireland Operations Ltd's registered address at 70 Sir John Rogerson's Quay, Dublin 2, Ireland.
- Germany: Customers in Germany may contact Microsoft customer support in order to be granted access to the account. Customers must provide proof of legal successorship and the following documentation:
- A copy of the death certificate.
- A copy of the ID or passport of the deceased person.
- A copy of the certificate of inheritance (Erbschein) or other documentation from a court that proves sole heirship, or names and addresses of all heirs and consent that you are entitled to act on their behalf.
- China: For customers in China, you may contact Microsoft customer support for your legitimate and justified interest, in order to be granted access to the deceased customer's account. You must provide the following documents:
- A copy of the death certificate, de-registration of household, or other official document proving the death of the account holder.
- A document that can prove your relationship to the deceased account holder as a "close relative", such as a Marriage Certificate, Birth Certificate, or Household Register (Hukou).
- A copy of your ID or passport.
- A signed statement (at least includes the intent for the access and the account info).
For more detailed information, please refer to the official documentation: Accessing Outlook.com, OneDrive and other Microsoft services when someone has died.
I hope this will help and you can get the memories important to you quickly :)