This section is focussed on Gmail, because it is so dominant
Because it is the one electronic identifier of a person that governments, banks, industry and social media can rely on.
They may use their own tools when they have set-up the first communication – but they will be proprietary.
Why not Messenger, Telegram or text
Because Messenger, Telegram and more are proprietary. Even if they are encrypted, these companies know the algorithms, they will be snapshotting messages before encryption – so they are not secure. Further, Messenger, Facebook are likely to get broken up in the next few years because of monopolies commission – you cannot base your country standards on commercially controlled organisations – where foreign governments may influence decisions.
Text is limited in its use and sending of attachments. Phone numbers only apply to a person for as long as they pay the next phone bill.
Choosing a mailbox name – what is good, what should be avoided
Sending and receiving emails, attachments
Explaining use of subject line.
Explaining use of To, cc, bcc
Explaining Alias and how to use it
Use of calendar (why use and benefits)