I'm using JavaMail's IMAP Store.
When opening the inbox, is it safe to assume that the name is always called "INBOX"?
IMAPFolder folder = (IMAPFolder) store.getFolder("INBOX");
Or is the "inbox" name nothing special and on a Swedish IMAP server it could be called "inkorg"?
I guess this same question applies equally to IMAP in general, beyond JavaMail.
Yes. Additionally, according to RFC 3501: INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1, INBOX has a number of special behaviors to boot:
5.1. Mailbox Naming
The case-insensitive mailbox name INBOX is a special name reserved to mean "the primary mailbox for this user on this server". The interpretation of all other names is implementation-dependent.
6.3.3. CREATE Command
It is an error to attempt to create INBOX or a mailbox with a name that refers to an extant mailbox.
6.3.4. DELETE Command
It is an error to attempt to delete INBOX or a mailbox name that does not exist.
6.3.5. RENAME Command
Renaming INBOX is permitted, and has special behavior. It moves all messages in INBOX to a new mailbox with the given name, leaving INBOX empty. If the server implementation supports inferior hierarchical names of INBOX, these are unaffected by a rename of INBOX.