My understanding, based upon Common Law in England & Wales, is once something is sent to a solicitor, it is subject to Legal Privilege.
If the solicitor is unable to open an emailed document, say because it is password protected with an unknown password, would the contents still be subject to Legal Privilege without being seen?
If the solicitor refused to store it on their email server, because it was unreadable, and they deleted the email, would it still have Legal Privilege?
For this question, assume that the sender knows the password and is happy to provide it at a future date, when they want their solicitor to view the document.