disable mailbox subfolders like "Spam"?

[ilf]

I retrieve mail via POP3. But Stalwart POP3 does not actually give me all mails. Stalwart moves some emails to a "Spam/" subfolder, which is only accessible via IMAP.

How can I get all mails directly into the Inbox - and disable any subfolders?

[mdecimus]

Disable the spam filter in that case. POP3 does not support folders.

[ilf]

@mdecimus: Thanks for the reply.

I am aware that POP3 does not support folders. That's why I am asking how to disable the Stalwart default behavior (using folders) to use another Stalwart feature (POP3 protocol).

I am not sure disabling the spam filter is appropriate. I still want Stalwart to filter spam to reject spam messages and deliver non-spam to the inbox. I just don't want a third tier to move messages with a certain spam threshold between certain spam (rejected) and certain non-spam (inbox) to a subfolder (spam). Other mail-servers allow this.

If disabling the spam filter is the only solution: How can I do that for one account/mailbox? I certainly don't want to disable the spam filter for an entire Stalwart instance and all its accounts.

[mdecimus]

It is not possible to disable folders. You could create a Sieve script that drops any messages classified a spam so they never get to the Junk Mail folder, but I don't think it's a good idea. If there is a classification mistake you will be losing a legitimate message.

[ilf]

I don't want to drop all mail that Stalwart classifies as ham. Our setup is new, and there are quite a few false positives.

I tried creating a Sieve script to move all messages from the Spam/ subfolder (back) to the inbox:

require ["fileinto"];

if folder :is "Spam" {
  fileinto "INBOX";
}

But this doesn't work. Stalwart still puts mail into the Spam subfolder.

Update: According to checksieve.com, "folder" is an "unrecognized test".

I would appreciate a way to achieve this, with Sieve or any other way.

Forcing users to use folders forces users to use IMAP/JMAP. I believe a mail server should be usable with POP3.

[ilf]

This sieve script also does not work:

require ["fileinto"];

if header :contains "X-Spam-Status" "Yes" {
  fileinto "INBOX";
}

Stalwart still puts mail into the Spam subfolder.

Can you please provide a way to achieve this?