One of the core problems with standard e-mail accounts is that business communications accumulate in individual accounts in a way that ensures they are not routinely accessible even to close colleagues.
This was brought home to me when I worked with an organisation that had shared drives, a collaboration tool, and an electronic records system, but who conducted most of its business through e-mail. A key part of their work was influencing and managing relations with external stakeholders, and the communications with those external stakeholders were for the most part only captured in e-mail.
A practice arose that when an individual left to take up another post elsewhere in the organisation, then the internal person replacing them would ask that individual to make an archive ( .pst) file of their e-mail account. Sometimes the individual agreed, and left them a copy of their e-mails on the shared drive. Sometimes they said no.
The practice was not officially supported or condoned (though it was not outlawed either).
This is a succession planning issue. Staff starting a new role often need to see the e-mail of there predecessor, in order to carry on with the working relationships of there predecessor. One person told me that she had transferred roles several times, and she had found it significantly more difficult to get to grips with a role when her predecessor had not provided her with an an e-mail .pst archive.
There is an element of absurdity to the situation. There was no benefit to the organisation for e-mail to be duplicated to a flakey .pst file sitting precariously on a shared drive. The organisation already held all of each outgoing post-holder’s e-mails, it just had no way of letting their successors see them.
The presence of personal communications mixed in with business communications means there is no purely technical solution to this problem.