> To prevent phishing, any chat service will suffice; an open protocol isn't necessary, as you don't intend to engage with ppl outside your org. The same could

> To prevent phishing, any chat service will suffice; an open protocol isn't necessary, as you don't intend to engage with ppl outside your org. The same could be accomplished with email if you only allow connections to the SMTP and IMAP server from within the corporate network. That is, nothing external can connect to those servers, which is fine if it's only used for internal communication.