Conceptually you're pretty much there, sir. Gmail is mostly just an interface to googles mail servers.

Gmail's UI doesn't do the actual deleting of email, it just instructs the email server to delete it.

However, I have no idea how the email servers behind that are actually configured. I wouldn't be surprised if emails are actually just hidden or archived but they'll "look" like they've been deleted.

Hope this helps.

Thanks, it does. I'm trying to conceptually understand how some of this works (completely devoid of any CS background other than basic code knowledge, but even that... Yikes). So this helps.

Depends on how the server is implemented.

Most deletions move it to a Trash folder either via the UI or IMAP and eventually the trash is emptied.

But even after that the server may have access to the email for some period of time for undelete/restore.

And of course any backups.

I'm pretty sure it takes a while for an email to be properly deleted in most online email systems, as it will have to flush through replicas, backups, etc. for a while.

Some metadata about emails may also be stored permanently out of the email system.

There is no guarantee that an email service provider deletes all copies of an email when you press 'delete' on the email, but most likely after a while the email will not be recoverable.

It _really_ depends on so many things.

This helps. Thanks. I'm trying get a conceptual understanding of the relationship between "the server" (which I'm only just starting to understand) and the UI/UX.

Whatever the "server" is, that would be an implementation detail, unless your question if more about the IMAP and POP3 protocols and what they are "supposed to do".