Email "Archive" Question

[Bram Zerbe]

I'm having trouble finding anything in the documentation...
How can I configure postfix to have the ability to archive emails, not
as an archive for legal purposes, but in the way that gmail/outlook/any
other major email service does archiving?
After adding my email server to my phone with IMAP, it gives me a
message saying that "The following accounts don't allow you to archive,
messages will be deleted instead."
How can I fix this?