diff --git a/Esp-rbl.cf b/Esp-rbl.cf
index a2dbb43..d0162e0 100644
--- a/Esp-rbl.cf
+++ b/Esp-rbl.cf
@@ -100,6 +100,16 @@ ifplugin Mail::SpamAssassin::Plugin::Esp
     tflags      RBL_ESP_KEYSENDER	net
   endif
 
+  header        ESP_KLAVIYO		eval:esp_klaviyo_check()
+  describe      ESP_KLAVIYO		Message from Klaviyo abused account
+  score         ESP_KLAVIYO		0.01
+
+  ifplugin Mail::SpamAssassin::Plugin::AskDNS
+    askdns      RBL_ESP_KLAVIYO		_KLAVIYOID_.klaviyo.espbl.snb.it A 127.0.0.1
+    describe    RBL_ESP_KLAVIYO		Esp Klaviyo Id blacklist
+    tflags      RBL_ESP_KLAVIYO		net
+  endif
+
   header        ESP_MAILCHIMP    eval:esp_mailchimp_check()
   describe      ESP_MAILCHIMP    Message from Mailchimp abused account
   score		ESP_MAILCHIMP    0.01
@@ -318,6 +328,13 @@ if (version >= 4.000000)
     describe    RBL_ESP_KEYSENDER     Esp Keysender Id blacklist
     tflags      RBL_ESP_KEYSENDER     net
 
+    header      __ESP_KLAVIYO_MSG     exists:X-Kmail-Message
+    header      __ESP_KLAVIYO_UID     X-Kmail-Account =~ /(?<KLAVIYO_UID>.*)/
+    header      __ESP_KLAVIYO_RBL     eval:check_hashbl_tag('klaviyo.espbl.snb.it/A', 'raw', 'KLAVIYO_UID', '^127\.')
+    meta        RBL_ESP_KLAVIYO       ( __ESP_KLAVIYO_MSG && __ESP_KLAVIYO_RBL )
+    describe    RBL_ESP_KLAVIYO       Esp Klaviyo Id blacklist
+    tflags      RBL_ESP_KLAVIYO       net
+
     header      __ESP_MAILCHIMP_XM    X-Mailer =~ /MailChimp\s+Mailer/
     header      __ESP_MAILCHIMP_ID    X-MC-User =~ /^(?<MAILCHIMP_ID>[0-9a-z]{25})$/
     header      __ESP_MAILCHIMP_RBL   eval:check_hashbl_tag('mailchimp.espbl.snb.it/A', 'raw', 'MAILCHIMP_ID', '^127\.')
@@ -427,6 +444,7 @@ score       RBL_ESP_ECMESSENGER   4.0
 score       RBL_ESP_EMARSYS       4.0
 score       RBL_ESP_EXACTTARGET   4.0
 score       RBL_ESP_FXYN          4.0
+score       RBL_ESP_KLAVIYO       4.0
 score       RBL_ESP_MAILCHIMP     4.0
 score       RBL_ESP_MAILCHIMP_M   4.0
 score       RBL_ESP_MAILDOME      4.0
diff --git a/Esp.cf b/Esp.cf
index cb81b5f..f82ff8b 100644
--- a/Esp.cf
+++ b/Esp.cf
@@ -100,6 +100,13 @@ header		KEYSENDER	eval:esp_keysender_check()
 describe	KEYSENDER	Message from Keysender abused account
 score		KEYSENDER	5.0
 
+# -------- KLAVIYO --------
+klaviyo_feed /etc/mail/spamassassin/klaviyo_id.txt
+
+header		KLAVIYO		eval:esp_klaviyo_check()
+describe	KLAVIYO		Message from Klaviyo abused account
+score		KLAVIYO		5.0
+
 # -------- MAILCHIMP --------
 mailchimp_feed /etc/mail/spamassassin/mailchimp_id.txt
 
diff --git a/Esp.pm b/Esp.pm
index e5d06f8..3232c71 100644
--- a/Esp.pm
+++ b/Esp.pm
@@ -67,6 +67,7 @@ sub new {
   $self->register_eval_rule('esp_exacttarget_check',  $Mail::SpamAssassin::Conf::TYPE_HEAD_EVALS);
   $self->register_eval_rule('esp_fxyn_check',  $Mail::SpamAssassin::Conf::TYPE_HEAD_EVALS);
   $self->register_eval_rule('esp_keysender_check',  $Mail::SpamAssassin::Conf::TYPE_HEAD_EVALS);
+  $self->register_eval_rule('esp_klaviyo_check',  $Mail::SpamAssassin::Conf::TYPE_HEAD_EVALS);
   $self->register_eval_rule('esp_mailchimp_check',  $Mail::SpamAssassin::Conf::TYPE_HEAD_EVALS);
   $self->register_eval_rule('esp_maildome_check',  $Mail::SpamAssassin::Conf::TYPE_HEAD_EVALS);
   $self->register_eval_rule('esp_mailgun_check',  $Mail::SpamAssassin::Conf::TYPE_HEAD_EVALS);
@@ -132,6 +133,9 @@ Usage:
   esp_keysender_check()
     Checks for Keysender abused accounts
 
+  esp_klaviyo_check()
+    Checks for Klaviyo abused accounts
+
   esp_mailchimp_check()
     Checks for Mailchimp abused accounts
 
@@ -235,6 +239,11 @@ Files can be separated by a comma.
 A list of files with abused Keysender accounts.
 Files can be separated by a comma.
 
+=item klaviyo_feed [...]
+
+A list of files with abused Klaviyo accounts.
+Files can be separated by a comma.
+
 =item mailchimp_feed [...]
 
 A list of files with abused Mailchimp accounts.
@@ -353,6 +362,9 @@ FXYNID
 =item *
 KEYSENDERID
 
+=item *
+KLAVIYOID
+
 =item *
 MAILCHIMPID
 
@@ -460,6 +472,12 @@ sub set_config {
     type => $Mail::SpamAssassin::Conf::CONF_TYPE_STRING,
     }
   );
+  push(@cmds, {
+    setting => 'klaviyo_feed',
+    is_admin => 1,
+    type => $Mail::SpamAssassin::Conf::CONF_TYPE_STRING,
+    }
+  );
   push(@cmds, {
     setting => 'mailchimp_feed',
     is_admin => 1,
@@ -559,6 +577,7 @@ sub finish_parsing_end {
   $self->_read_configfile('fordem_feed', 'FORDEM');
   $self->_read_configfile('fxyn_feed', 'FXYN');
   $self->_read_configfile('keysender_feed', 'KEYSENDER');
+  $self->_read_configfile('klaviyo_feed', 'KLAVIYO');
   $self->_read_configfile('mailchimp_feed', 'MAILCHIMP');
   $self->_read_configfile('maildome_feed', 'MAILDOME');
   $self->_read_configfile('mailgun_feed', 'MAILGUN');
@@ -847,6 +866,23 @@ sub esp_keysender_check {
   return _hit_and_tag($self, $pms, $uid, 'KEYSENDER', 'Keysender', 'KEYSENDERID', $opts);
 }
 
+sub esp_klaviyo_check {
+  my ($self, $pms, $opts) = @_;
+  my $uid;
+
+  # return if X-Kmail-Message is not set
+  my $xkm = $pms->get("X-Kmail-Message", undef);
+
+  if(not defined $xkm) {
+    return;
+  }
+
+  $uid = $pms->get("X-Kmail-Account", undef);
+  return if not defined $uid;
+
+  return _hit_and_tag($self, $pms, $uid, 'KLAVIYO', 'Klaviyo', 'KLAVIYOID', $opts);
+}
+
 sub esp_mailchimp_check {
   my ($self, $pms, $opts) = @_;
   my $mailchimp_id;
@@ -1138,6 +1174,7 @@ sub has_esp_emarsys_check { 1 };
 sub has_esp_exacttarget_check { 1 };
 sub has_esp_fxyn_check { 1 };
 sub has_esp_keysender_check { 1 };
+sub has_esp_klaviyo_check { 1 };
 sub has_esp_mailchimp_check { 1 };
 sub has_esp_maildome_check { 1 };
 sub has_esp_mailgun_check { 1 };