While a properly established system should not have this problem, it is always a risk. E mail appears casual but actually creates a record. Some workers have been surprised to see their love notes distributed across the network. Confidential information has been routed to the wrong person. Some e mail systems do not include spell checkers, creating a bad impression of the sender's competence.
Security is always an issue with e mail.
With internal office e mail or Internet e mail, messages must be assumed to be accessible to those who really want them not just to intended recipients. Internet e mail should not be used for confidential client communications, unless it is encrypted. Office e mail may remain on a server and accessible to those who are determined to get the information. Authentication of messages can be difficult. It is possible to send messages across the internet which give the appearance of having come from an individual but which really did not.