Internal emails from my own domain go to spam.

I have a problem that I have not been able to solve, I turn to you friends,

Every time I send internal emails, they all arrive to the spam folder, I use relay (proxmox mail gateway) for the reception and sending of emails, but I have noticed a value DMARC_FAIL_REJECT=9 which I think is affecting the spam score.

Received: from mail.hospital-infectologia.gob.ec (LHLO
mail.hospital-infectologia.gob.ec) (192.168.80.500) by
mail.hospital-infectologia.gob.ec with LMTP; Mon, 13 May 2024 16:29:07
-0500 (ECT)
Received: from localhost (localhost [127.0.0.1])
by mail.hospital-infectologia.gob.ec (Postfix) with ESMTP id 83DB4605909
for <perez.loza@hospital-infectologia.gob.ec>; Mon, 13 May 2024 16:29:07 -0500 (-05)
X-Spam-Flag: YES
X-Spam-Score: 10.575
X-Spam-Level: **********
X-Spam-Status: Yes, score=10.575 required=3.2 tests=[ALL_TRUSTED=-1,
DKIM_INVALID=0.1, DKIM_SIGNED=0.1, DMARC_FAIL_REJECT=9, HELO_NO_DOMAIN=1.098,
HTML_MESSAGE=0.001, RDNS_NONE=1.274, TVD_SPACE_RATIO=0.001,
URIBL_BLOCKED=0.001] autolearn=no autolearn_force=no
Authentication-Results: mail.hospital-infectologia.gob.ec (amavis);
dkim=neutral reason="invalid (public key: not available)"
header.d=hospital-infectologia.gob.ec
Received: from mail.hospital-infectologia.gob.ec ([127.0.0.1])
by localhost (mail.hospital-infectologia.gob.ec [127.0.0.1]) (amavis, port 10032)
with ESMTP id s3Td1ONEeOaj for <perez.loza@hospital-infectologia.gob.ec>;
Mon, 13 May 2024 16:29:07 -0500 (-05)

however when I send emails to gmail, hotmail, yahoo the emails arrive to the received folder correctly, the problem only occurs when I send internally.