I was wondering about the cause of an e-mail incoming from third party having ***SPAM*** in its subject. Is problem on sending server, recipient mail server or the e-mail client software?

e-mail source code/headers:

Received: from localhost (localhost.localdomain [127.0.0.1])
by remote.mail-server.tld (Postfix) with ESMTP id ***
for <[email protected]>; datehere
X-Spam-Flag: YES
X-Spam-Score: 3.056
X-Spam-Level: ***
X-Spam-Status: Yes, score=3.056 required=3 tests=[BASE64_LENGTH_78_79=0.1,
BASE64_LENGTH_79_INF=2.019, DKIM_INVALID=0.1, DKIM_SIGNED=0.1,
HEADER_FROM_DIFFERENT_DOMAINS=0.001, HTML_MESSAGE=0.001,
HTML_MIME_NO_HTML_TAG=0.635, MIME_HTML_ONLY=0.1, NO_RELAYS=-0.001,
URIBL_BLOCKED=0.001] autolearn=no autolearn_force=no

from my research it suggests that it may be the Apache SpamAssassin software which is a web server software suggesting the problem is on the sender server (web hosting server). But my web hosting account which part is my recipient mailbox also feature this antispam software (wchich in my case is disabled).

What do you think about this? Does it mean that the website i am registered to marked its own mail as SPAM?