I disagree. Email is a decidedly different format than chat or chat history. IMO it's far easier to find things in email and (ironically) far easier to have a "paper trail" of conversation on a topic; it's all there in the most recent email. You can also conveniently sort on subject, sender, timeframes, etc. Chat is much more limited and IMO often a royal PITA if you have numerous channels, which fragments things. No such fragmentation with email; it's all there in one place.
Ah, nope. Any one email trail, assuming a series of simply replies back and forth, is just the same functionally as a copy/reply chat conversation between two users. The only
functional difference is chats are stored centrally in one repository and shared, while email messages are (usually) stored in separate repositories. This separation is what historically has provided any email retention security (let's assume perfect backups
).
Of course, there's actually far more complexity to this, technically. For example, if two users share a cloudy email facility, e.g. Gmail, the emails
are in a central shared repository, so their email trails are, in effect, chat conversations. They are also subject to whatever Gmail's retention security model is at the time (LOL).
You also need to take into account if replying to chats and emails includes quoting what they are replying to. In neither case is this absolutely necessary, but conventionally, email users do while chat users don't.
I take the point about filing emails while not filing chats. But again, that's convention, not any particular technical limitation. Most modern chat facilities do have ways to file and catagorise chats, but perhaps not quite in the same way as email folders. In short, it's whatever you get used to, and what you use the tools for.