The clients doing SMTP themselves allows them to communicate sending failures to the user. How would you do that for an email just sitting in an IMAP folder? You’d need to define and integrate some “sending” protocol into IMAP.
Furthermore, there are many use cases where clients only send, like notification emails or sending reports. Those use cases would become more complicated if those clients were forced to use IMAP. For one, you wouldn’t want to give all of them access to all email in other folders — or even to emails in the outbox sent by other clients.
Re:Why SMTP still matters today
by qwerty456127 on Friday August 11, 2023 @06:37AM
(#37087131)
Makes sense, thanks.
> The clients doing SMTP themselves allows them to communicate sending failures to the user. How would you do that for an email just sitting in an IMAP folder?
I would introduce a folder for logs.
However, once everyone rolled out IMAP and deprecated (explicitly or implicitly) POP, why didn't they also deprecate SMTP (for clients) in favour of clients just putting outgoing mail to an Outbox folder over IMAP?