Email visibility in Zoho CRM has changed in a way worth knowing about if you're used to an older setup, particularly around the distinction between a standalone Emails tab and the Emails related list on individual records.
Every record type that supports email, such as Leads, Contacts, Deals, Purchase Orders, Sales Orders, Quotes, Cases, and Invoices, has an Emails related list on its detail page. This shows the email correspondence tied specifically to that record, and is also where you click Send Mail to compose a new email from within that record.
If you're used to checking a single "All" emails view rather than looking at emails record by record, this is the change behind that shift: the standalone tab that once gave you that combined view is going away, and the Emails related list on each individual record is becoming the primary place to see email activity going forward.
Rather than one central email inbox view inside CRM, email activity is now tied to the specific record it relates to. This is generally more useful for context while working a specific Lead or Deal, but does mean there isn't a single unified list of every email across your whole CRM account the way the older tab provided.