diff --git a/addons/base_setup/models/res_config_settings.py b/addons/base_setup/models/res_config_settings.py
index 32981b403fb..387b4a6cc5e 100644
--- a/addons/base_setup/models/res_config_settings.py
+++ b/addons/base_setup/models/res_config_settings.py
@@ -15,9 +15,6 @@ class ResConfigSettings(models.TransientModel):
     user_default_rights = fields.Boolean(
         "Default Access Rights",
         config_parameter='base_setup.default_user_rights')
-    external_email_server_default = fields.Boolean(
-        "Use Custom Email Servers",
-        config_parameter='base_setup.default_external_email_server')
     module_base_import = fields.Boolean("Allow users to import data from CSV/XLS/XLSX/ODS files")
     module_google_calendar = fields.Boolean(
         string='Allow the users to synchronize their calendar  with Google Calendar')
diff --git a/addons/hr_expense/views/res_config_settings_views.xml b/addons/hr_expense/views/res_config_settings_views.xml
index 45e108356c5..a0f5a714729 100644
--- a/addons/hr_expense/views/res_config_settings_views.xml
+++ b/addons/hr_expense/views/res_config_settings_views.xml
@@ -14,18 +14,19 @@
                                      help="Create expenses from incoming emails"
                                      title="Send an email to this email alias with the receipt in attachment to create an expense in one click. If the first word of the mail subject contains the category's internal reference or the category name, the corresponding category will automatically be set. Type the expense amount in the mail subject to set it on the expense too.">
                                 <field name="hr_expense_use_mailgateway"/>
-                                <div class="content-group" invisible="not hr_expense_use_mailgateway or alias_domain in ['localhost', '', False]">
-                                    <div class="mt16">
+                                <div class="content-group" invisible="not hr_expense_use_mailgateway or not alias_domain_id">
+                                    <div class="mt16 d-flex align-items-start">
                                         <label for="hr_expense_alias_prefix" string="Alias" class="o_light_label"/>
                                         <field name="hr_expense_alias_prefix" class="oe_inline ps-2"/>
                                         <span>@</span>
-                                        <field name="alias_domain" class="oe_inline" readonly="1" force_save="1"/>
+                                        <field name="alias_domain_id" class="oe_inline" placeholder="e.g. domain.com"
+                                               options="{'no_create': True, 'no_open': True}"/>
                                     </div>
                                 </div>
-                                <div class="content-group" invisible="not hr_expense_use_mailgateway or alias_domain not in ['localhost', '', False]">
+                                <div class="content-group" invisible="not hr_expense_use_mailgateway or alias_domain_id">
                                     <div class="mt16">
                                         <button type="action" name="base_setup.action_general_configuration"
-                                                icon="oi-arrow-right" string="Setup your domain alias" class="btn-link"/>
+                                                icon="oi-arrow-right" string="Setup your alias domain" class="btn-link"/>
                                     </div>
                                 </div>
                             </setting>
diff --git a/addons/mail/models/res_config_settings.py b/addons/mail/models/res_config_settings.py
index 470200d2532..c57b86d15e3 100644
--- a/addons/mail/models/res_config_settings.py
+++ b/addons/mail/models/res_config_settings.py
@@ -12,9 +12,13 @@ class ResConfigSettings(models.TransientModel):
     the alias domain. """
     _inherit = 'res.config.settings'
 
+    external_email_server_default = fields.Boolean(
+        "Use Custom Email Servers",
+        config_parameter='base_setup.default_external_email_server')
     fail_counter = fields.Integer('Fail Mail', compute="_compute_fail_counter")
-    alias_domain = fields.Char(
-        'Alias Domain', config_parameter='mail.catchall.domain',
+    alias_domain_id = fields.Many2one(
+        'mail.alias.domain', 'Alias Domain',
+        readonly=False, related='company_id.alias_domain_id',
         help="If you have setup a catch-all email domain redirected to the Odoo server, enter the domain name here.")
     module_google_gmail = fields.Boolean('Support Gmail Authentication')
     module_microsoft_outlook = fields.Boolean('Support Outlook Authentication')
diff --git a/addons/mail/views/res_config_settings_views.xml b/addons/mail/views/res_config_settings_views.xml
index 767acd38c3e..ddb40d0ae2a 100644
--- a/addons/mail/views/res_config_settings_views.xml
+++ b/addons/mail/views/res_config_settings_views.xml
@@ -33,7 +33,18 @@
                                 </div>
                             </div>
                         </setting>
-                        <setting string="Use a Gmail Server" help="Send and receive emails through your Gmail account." documentation="https://console.developers.google.com/" invisible="not external_email_server_default">
+                        <setting id="email-alias-setting" string="Alias Domain"
+                                 help="Use different domains for your mail aliases"
+                                 company_dependent="1"
+                                 documentation="/applications/general/email_communication/email_domain.html#be-spf-compliant">
+                            <span class="me-1">@</span>
+                            <field name="alias_domain_id" placeholder="e.g. domain.com"
+                                   options="{'no_create_edit': True}"/>
+                        </setting>
+                        <setting string="Use a Gmail Server"
+                                 help="Send and receive emails through your Gmail account."
+                                 documentation="https://console.developers.google.com/"
+                                 invisible="not external_email_server_default">
                             <field name="module_google_gmail"/>
                             <div class="content-group" invisible="not module_google_gmail" id="msg_module_google_gmail">
                                 <div class="mt16 text-warning"><strong>Save</strong> this page and come back here to set up the feature.</div>
@@ -51,9 +62,6 @@
                                 </div>
                             </div>
                         </setting>
-                        <setting id="email-alias-setting" string="Alias Domain" help="Use a different domain for your mail aliases" documentation="/applications/general/email_communication/email_domain.html#be-spf-compliant">
-                            <span>@<field name="alias_domain" placeholder='e.g. "mycompany.com"'/></span>
-                        </setting>
                         <setting help="Add your twilio credentials for ICE servers">
                             <field name="use_twilio_rtc_servers"/>
                             <div class="content-group"  invisible="not use_twilio_rtc_servers">