diff --git a/addons/mail/static/src/js/chatter.js b/addons/mail/static/src/js/chatter.js
index 164a24cd7b8..9f0299565d2 100644
--- a/addons/mail/static/src/js/chatter.js
+++ b/addons/mail/static/src/js/chatter.js
@@ -31,6 +31,7 @@ var Chatter = Widget.extend({
         discard_record_changes: '_onDiscardRecordChanges',
         reload_attachment_box: '_onReloadAttachmentBox',
         reload_mail_fields: '_onReloadMailFields',
+        reset_suggested_partners: '_onResetSuggestedPartners',
     },
     events: {
         'click .o_chatter_button_new_message': '_onOpenComposerMessage',
@@ -68,6 +69,7 @@ var Chatter = Widget.extend({
         // suggestions as well once fetched
         this._mentionPartnerSuggestions = this.call('mail_service', 'getMentionPartnerSuggestions');
         this._mentionSuggestions = this._mentionPartnerSuggestions;
+        this._suggestedPartnersProm = undefined;
 
         if (mailFields.mail_activity) {
             this.fields.activity = new Activity(this, mailFields.mail_activity, record, options);
@@ -406,6 +408,12 @@ var Chatter = Widget.extend({
             }
         }).then(always).guardedCatch(always);
     },
+    /**
+     * @private
+     */
+    _resetSuggestedPartners() {
+        this._suggestedPartnersProm = undefined;
+    },
     /**
      * @private
      * @param {Object} record
@@ -422,9 +430,9 @@ var Chatter = Widget.extend({
                 default_res_id: record.res_id || false,
                 default_model: record.model || false,
             };
-            // reset the suggested_partners_def to ensure a reload of the
+            // reset the _suggestedPartnersProm to ensure a reload of the
             // suggested partners when opening the composer on another record
-            this.suggested_partners_def = undefined;
+            this._resetSuggestedPartners();
         }
         this.record = record;
         this.recordName = record.data.display_name;
@@ -475,6 +483,7 @@ var Chatter = Widget.extend({
         });
     },
 
+
     //--------------------------------------------------------------------------
     // Handlers
     //--------------------------------------------------------------------------
@@ -537,8 +546,8 @@ var Chatter = Widget.extend({
     },
     _onOpenComposerMessage: function () {
         var self = this;
-        if (!this.suggested_partners_def) {
-            this.suggested_partners_def = new Promise(function (resolve, reject) {
+        if (!this._suggestedPartnersProm) {
+            this._suggestedPartnersProm = new Promise(function (resolve, reject) {
                 self._rpc({
                     route: '/mail/get_suggested_recipients',
                     params: {
@@ -546,7 +555,7 @@ var Chatter = Widget.extend({
                         res_ids: [self.context.default_res_id],
                     },
                 }).then(function (result) {
-                    if (!self.suggested_partners_def) {
+                    if (!self._suggestedPartnersProm) {
                         return; // widget has been reset (e.g. we just switched to another record)
                     }
                     var suggested_partners = [];
@@ -566,7 +575,7 @@ var Chatter = Widget.extend({
                 });
             });
         }
-        this.suggested_partners_def.then(function (suggested_partners) {
+        this._suggestedPartnersProm.then(function (suggested_partners) {
             self._openComposer({ isLog: false, suggested_partners: suggested_partners });
         });
     },
@@ -610,6 +619,14 @@ var Chatter = Widget.extend({
             keepChanges: true,
         });
     },
+    /**
+     * @private
+     * @param {OdooEvent} ev
+     */
+    _onResetSuggestedPartners(ev) {
+        ev.stopPropagation();
+        this._resetSuggestedPartners();
+    },
     /**
      * @private
      */
diff --git a/addons/mail/static/src/js/composers/chatter_composer.js b/addons/mail/static/src/js/composers/chatter_composer.js
index 3109528cfed..4b20e5b2d25 100644
--- a/addons/mail/static/src/js/composers/chatter_composer.js
+++ b/addons/mail/static/src/js/composers/chatter_composer.js
@@ -224,6 +224,9 @@ var ChatterComposer = BasicComposer.extend({
                         message.context = _.defaults({}, message.context, {
                             mail_post_autofollow: true,
                         });
+                        if (partnerIDs.length) {
+                            self.trigger_up('reset_suggested_partners');
+                        }
                         resolve(message);
                     });
                 } else {
diff --git a/addons/mail/static/tests/chatter_tests.js b/addons/mail/static/tests/chatter_tests.js
index 1c57150e28c..f0f3394c1e1 100644
--- a/addons/mail/static/tests/chatter_tests.js
+++ b/addons/mail/static/tests/chatter_tests.js
@@ -3074,6 +3074,82 @@ QUnit.test('chatter: mention prefetched partners (followers & employees)', async
     form.destroy();
 });
 
+QUnit.test('chatter: display suggested partners only once', async function (assert) {
+    assert.expect(3);
+
+    let isMessageSent = false;
+
+    const form = await createView({
+        View: FormView,
+        model: 'partner',
+        data: this.data,
+        services: this.services,
+        arch: `
+            <form string="Partners">
+                <sheet>
+                    <field name="foo"/>
+                </sheet>
+                <div class="oe_chatter">
+                    <field name="message_follower_ids" widget="mail_followers"/>
+                    <field name="message_ids" widget="mail_thread" options="{'display_log_button': True}"/>
+                </div>
+            </form>`,
+        res_id: 2,
+        async mockRPC(route, args) {
+            if (route === '/mail/read_followers') {
+                return {
+                    followers: [],
+                    subtypes: [],
+                };
+            }
+            if (route === '/mail/get_suggested_recipients') {
+                if (isMessageSent) {
+                    return {
+                        2: [],
+                    };
+                }
+                return {
+                    2: [[2, "Jack <jack@example.com>", "Partner Profile"]],
+                };
+            }
+            if (args.method === 'message_post') {
+                isMessageSent = true;
+                return 57923;
+            }
+            if (args.method === 'message_format') {
+                return [{
+                    author_id: ["42", "Me"],
+                    model: 'partner',
+                }];
+            }
+            return this._super(route, args);
+        },
+        session: {},
+    });
+
+    await testUtils.dom.click(form.$('.o_chatter_button_new_message'));
+    const $input = form.$('.oe_chatter .o_composer_text_field:first()');
+    assert.containsOnce(
+        form,
+        'div.o_composer_suggested_partners input',
+        "should show one suggested recipient");
+    assert.strictEqual(
+        form.$('div.o_composer_suggested_partners label').text().replace(/\s+/g, ''),
+        "Jack(jack@example.com)",
+        "should have the correct label");
+
+    $input.val("BBQ and beers tonight! Are you in?");
+    await testUtils.dom.click(form.$('.o_composer_button_send'));
+    // Open composer for new message
+    await testUtils.dom.click(form.$('.o_chatter_button_new_message'));
+    assert.containsNone(
+        form,
+        'div.o_composer_suggested_partners input',
+        "should no longer show the suggested recipient");
+
+    form.destroy();
+});
+
 QUnit.module('FieldMany2ManyTagsEmail', {
     beforeEach: function () {
         this.data = {