diff --git a/addons/mass_mailing/static/src/js/mailing_m2o_filter.js b/addons/mass_mailing/static/src/js/mailing_m2o_filter.js
index 36e5f7c2b09..4364266fdd1 100644
--- a/addons/mass_mailing/static/src/js/mailing_m2o_filter.js
+++ b/addons/mass_mailing/static/src/js/mailing_m2o_filter.js
@@ -63,8 +63,18 @@ export class FieldMany2OneMailingFilter extends Many2OneField {
         }
         // By default, domains in recordData are in string format, but adding / removing a leaf from domain widget converts
         // value into object, so we use 'Domain' class to convert them in same (string) format, allowing proper comparison.
-        const recordDomain = new Domain(this.props.record.data[this.props.domain_field] || []).toString();
-        const filterDomain = new Domain(this.props.record.data.mailing_filter_domain || []).toString();
+        let recordDomain;
+        let filterDomain;
+        try {
+            recordDomain = new Domain(this.props.record.data[this.props.domain_field] || []).toString();
+            filterDomain = new Domain(this.props.record.data.mailing_filter_domain || []).toString();
+        } catch {
+            // Don't raise a traceback if a domain set manually doesn't match the format expected.
+            // This can happen when we unfocus the domain editor
+            this.filter.canSaveFilter = false;
+            this.filter.canRemoveFilter = false;
+            return;
+        }
 
         const modelFieldElement = this.props.model_field && document.querySelector(
             `input#${this.props.model_field},div [name="${this.props.model_field}"]`);
@@ -81,6 +91,7 @@ export class FieldMany2OneMailingFilter extends Many2OneField {
             || value.length
             || this.state.isFloating
             || filterDomain !== recordDomain;
+        this.filter.canRemoveFilter = !this.filter.canSaveFilter
     }
 
     // HANDLERS
diff --git a/addons/mass_mailing/static/src/xml/mailing_filter_widget.xml b/addons/mass_mailing/static/src/xml/mailing_filter_widget.xml
index 4b95ad89508..d72e39ffbae 100644
--- a/addons/mass_mailing/static/src/xml/mailing_filter_widget.xml
+++ b/addons/mass_mailing/static/src/xml/mailing_filter_widget.xml
@@ -24,7 +24,7 @@
                         </div>
                     </MailingFilterDropdown>
                 </div>
-                <a t-attf-class="o_mass_mailing_remove_filter btn px-1 pt-1 pb-0 {{ this.filter.canSaveFilter ? 'd-none': '' }}" t-on-click="onRemoveFilter">
+                <a t-attf-class="o_mass_mailing_remove_filter btn px-1 pt-1 pb-0 {{ !this.filter.canRemoveFilter ? 'd-none': '' }}" t-on-click="onRemoveFilter">
                     <i class="fa fa-trash px-3 py-1 align-bottom" title="Remove from Favorites"/>
                 </a>
             </div>
diff --git a/addons/mass_mailing/static/tests/mass_mailing_favourite_filter_tests.js b/addons/mass_mailing/static/tests/mass_mailing_favourite_filter_tests.js
index f268c6b02cd..3fee3a1552d 100644
--- a/addons/mass_mailing/static/tests/mass_mailing_favourite_filter_tests.js
+++ b/addons/mass_mailing/static/tests/mass_mailing_favourite_filter_tests.js
@@ -409,6 +409,44 @@ QUnit.module('favorite filter widget', (hooks) => {
             "should not have option to remove filter because mailing domain is changed");
     });
 
+    QUnit.test('filter widget does not raise traceback when losing focus with unexpected domain format', async (assert) => {
+        assert.expect(4);
+
+        await makeView({
+            type: "form",
+            resModel: "mailing.mailing",
+            resId: 2,
+            serverData,
+            arch: `<form>
+                    <field name="display_name"/>
+                    <field name="subject"/>
+                    <field name="mailing_domain"/>
+                    <field name="mailing_model_name" invisible="1"/>
+                    <field name="mailing_model_id"/>
+                    <field name="mailing_filter_count"/>
+                    <field name="mailing_filter_domain" invisible="1"/>
+                    <field name="mailing_filter_id"
+                        widget="mailing_filter"
+                        options="{'no_create': '1', 'no_open': '1', 'domain_field': 'mailing_domain', 'model': 'mailing_model_id'}"/>
+                </form>`,
+        });
+
+        // Initial state of icons with no filter
+        assert.isVisible(fixture.querySelector('.o_mass_mailing_save_filter_container'),
+            "should have option to save filter if no filter is set");
+        assert.isNotVisible(fixture.querySelector('.o_mass_mailing_remove_filter'));
+
+        // Set incorrect domain format
+        await testUtils.editInput(fixture, "div[name='mailing_domain'] input", "[");
+        // Wait to lose the focus
+        await testUtils.nextTick();
+
+        assert.isNotVisible(fixture.querySelector('.o_mass_mailing_save_filter_container'),
+            "should not have option to save filter if domain format is incorrect");
+        assert.isNotVisible(fixture.querySelector('.o_mass_mailing_remove_filter'),
+            "should still not be visible");
+    });
+
     QUnit.test('filter widget works in edit and readonly', async (assert) => {
         assert.expect(4);