DomainKeys and DKIM neutral, messages not signed

So hey there! The title says it all, here's my domain: insight-os.com.br

DomainKeys Identified Email is enabled and the keys generated, but I still get neutral in check-auth@verifier.port25.com

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SPF check: pass DomainKeys check: neutral DKIM check: neutral Sender-ID check: pass SpamAssassin check: ham

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HELO hostname: node.insight-os.com.br Source IP: 104.223.78.144 mail-from: contact@insight-os.com.br

SPF check details:

Result: pass ID(s) verified: smtp.mailfrom=contact@insight-os.com.br DNS record(s): insight-os.com.br. SPF (no records) insight-os.com.br. 38400 IN TXT "v=spf1 a mx a:insight-os.com.br ip4:104.223.78.144 ?all" insight-os.com.br. 38400 IN A 104.223.78.144

DomainKeys check details:

Result: neutral (message not signed) ID(s) verified: header.From=contact@insight-os.com.br DNS record(s):

DKIM check details:

Result: neutral (message not signed) ID(s) verified:

NOTE: DKIM checking has been performed based on the latest DKIM specs (RFC 4871 or draft-ietf-dkim-base-10) and verification may fail for older versions. If you are using Port25's PowerMTA, you need to use version 3.2r11 or later to get a compatible version of DKIM.

Sender-ID check details:

Result: pass ID(s) verified: header.From=contact@insight-os.com.br DNS record(s): insight-os.com.br. SPF (no records) insight-os.com.br. 38400 IN TXT "v=spf1 a mx a:insight-os.com.br ip4:104.223.78.144 ?all" insight-os.com.br. 38400 IN A 104.223.78.144

SpamAssassin check details:

SpamAssassin v3.4.0 (2014-02-07)

Result: ham (0.7 points, 5.0 required)

pts rule name description

1.4 RCVD_IN_BRBL_LASTEXT RBL: No description available. [104.223.78.144 listed in bb.barracudacentral.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.2 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.5 BAYES_05 BODY: Bayes spam probability is 1 to 5% [score: 0.0118]