IMAP standard folder names - "Junk" or "Spam"

Unfortunately both are very common. Most of the OpenSource software I've found uses Junk, and most of the Proprietary software seems to use Spam. New users may be accustomed to either...

The only "solution" I've found is to use one or the other, and to do so very consistently. At home I use RoundCube as well, and I standardized on "Junk" long before. If I had chosen "Spam" I would simply change the default locations and button labels on RC so it matches. At work we use Exchange/Outlook, so "Spam" was the clear choice as everything was setup for it already (despite the fact that Outlook's buttons and menu options are for "Junk Mail").

It may be possible, depending on your server configuration, to have both folders linked to the same location. I've found this to cause confusion, more so than picking one or the other (users asked "What's the difference" despite both having the exact same content).

INBOX is part of the IMAP standard, the other three have generally been standardized on those names, but I've also seen "Sent Items" instead of "Sent", "Deleted" and "Deleted Items" instead of "Trash". "Drafts" is the only one I've never seen a variant of.

Luckily, RFC 6154 IMAP LIST Extension for Special-Use Mailboxes is here to help us, giving some standard mailbox attributes for identifying special-use mailboxes.

\Junk

• This mailbox is where messages deemed to be junk mail are held. Some server implementations might put messages here automatically. Alternatively, this might just be advice to a client-side spam filter.

While the proposed standard uses the name junk, it's possible to make a mailbox or maildir named Spam to have this special-use flag, and all the IMAP clients following the standard will know the purpose of this mailbox despite server-side filters are moving messages to the Spam folder.

Difference between Spam Mail and Junk Mail (and Ashley Poland) suggests that spam is a term for unsolicited mail, whereas junk is solicited mail. That's why spam can be rejected while junk gets moved to another folder. Statistically most clients uses Junk as the folder name, and Thunderbird has chosen it to differentiate. Leo A. Notenboom treats spam and junk as synonyms, and so does Wikipedia.

Additionally, Office 365 has a new category clutter for mail that isn't neither spam nor junk, but still something you usually ignore. That's similar to Bacn, email you want — but not right now, but we'll see whether clutter will get more widely accepted.