Always use email composer mini or email composer modeless dialog when composing within a record page.
Never use email composer full screen alongside the record page.
Always ensure that the email composer modeless dialog is used when record context is important to the message’s composition.
Never use email as a modal for composing an email because this will hide the case details, it is recommended to use either modeless dialog or email composer mini.
Always use the compact attachment card when using attachment cards in email composer. We do this so that we can save vertical space. This is applicable for all email composer types.
Never use default attachment cards with size information or meta data, This is applicable for all email composer types.