diff --git a/admin/freeposte/admin/models.py b/admin/freeposte/admin/models.py
index 17111fb2..28f05c60 100644
--- a/admin/freeposte/admin/models.py
+++ b/admin/freeposte/admin/models.py
@@ -55,24 +55,32 @@ class Address(Base):
     """
     __abstract__ = True
 
-    localpart = db.Column(db.String(80), primary_key=True, nullable=False)
+    localpart = db.Column(db.String(80), nullable=False)
 
     @declarative.declared_attr
     def domain_name(cls):
         return db.Column(db.String(80), db.ForeignKey(Domain.name),
-            primary_key=True, nullable=False)
+            nullable=False)
 
-    def __str__(self):
-        return '{0}@{1}'.format(self.localpart, self.domain_name)
-
-    def get_id(self):
-        return str(self)
+    # This field is redundant with both localpart and domain name.
+    # It is however very useful for quick lookups without joining tables,
+    # especially when the mail server il reading the database.
+    @declarative.declared_attr
+    def address(cls):
+        updater = lambda context: "{0}@{1}".format(
+            context.current_parameters["localpart"],
+            context.current_parameters["domain_name"],
+        )
+        return db.Column(db.String(255),
+            primary_key=True, nullable=False,
+            default=updater)
 
     @classmethod
     def get_by_email(cls, email):
-        localpart, domain = email.split('@', maxsplit=1)
-        # Get the user object
-        return cls.query.filter_by(domain_name=domain, localpart=localpart).first()
+        return cls.query.filter_by(address=email).first()
+
+    def __str__(self):
+        return self.address
 
 
 class User(Address):
@@ -102,6 +110,9 @@ class User(Address):
     is_active = True
     is_anonymous = False
 
+    def get_id(self):
+        return self.address
+
     pw_context = context.CryptContext(
         ["sha512_crypt", "sha256_crypt", "md5_crypt"]
     )
diff --git a/admin/freeposte/admin/templates/alias/list.html b/admin/freeposte/admin/templates/alias/list.html
index c595466a..2e5810b3 100644
--- a/admin/freeposte/admin/templates/alias/list.html
+++ b/admin/freeposte/admin/templates/alias/list.html
@@ -26,8 +26,8 @@ Alias list
     {% for alias in domain.aliases %}
     <tr>
       <td>
-        <a href="{{ url_for('.alias_edit', alias=alias.get_id()) }}" title="Edit"><i class="fa fa-pencil"></i></a>&nbsp;
-        <a href="{{ url_for('.alias_delete', alias=alias.get_id()) }}" onclick="return confirm('Are you sure?')" title="Delete"><i class="fa fa-trash"></i></a>
+        <a href="{{ url_for('.alias_edit', alias=alias.address) }}" title="Edit"><i class="fa fa-pencil"></i></a>&nbsp;
+        <a href="{{ url_for('.alias_delete', alias=alias.address) }}" onclick="return confirm('Are you sure?')" title="Delete"><i class="fa fa-trash"></i></a>
       </td>
       <td>{{ alias }}</td>
       <td>{{ alias.destination or '-' }}</td>
diff --git a/admin/freeposte/admin/templates/user/list.html b/admin/freeposte/admin/templates/user/list.html
index 7634ee48..23c025bd 100644
--- a/admin/freeposte/admin/templates/user/list.html
+++ b/admin/freeposte/admin/templates/user/list.html
@@ -28,14 +28,14 @@ User list
     {% for user in domain.users %}
     <tr>
       <td>
-        <a href="{{ url_for('.user_edit', user_email=user.get_id()) }}" title="Edit"><i class="fa fa-pencil"></i></a>&nbsp;
-        <a href="{{ url_for('.user_delete', user_email=user.get_id()) }}" onclick="return confirm('Are you sure?')" title="Delete"><i class="fa fa-trash"></i></a>
+        <a href="{{ url_for('.user_edit', user_email=user.address) }}" title="Edit"><i class="fa fa-pencil"></i></a>&nbsp;
+        <a href="{{ url_for('.user_delete', user_email=user.address) }}" onclick="return confirm('Are you sure?')" title="Delete"><i class="fa fa-trash"></i></a>
       </td>
       <td>
-        <a href="{{ url_for('.user_settings', user_email=user.get_id()) }}" title="Settings"><i class="fa fa-wrench"></i></a>&nbsp;
-        <a href="{{ url_for('.user_forward', user_email=user.get_id()) }}" title="Auto-forward"><i class="fa fa-share"></i></a>&nbsp;
-        <a href="{{ url_for('.user_reply', user_email=user.get_id()) }}" title="Auto-reply"><i class="fa fa-plane"></i></a>&nbsp;
-        <a href="{{ url_for('.user_fetchmail', user_email=user.get_id()) }}" title="Fetched accounts"><i class="fa fa-download"></i></a>&nbsp;
+        <a href="{{ url_for('.user_settings', user_email=user.address) }}" title="Settings"><i class="fa fa-wrench"></i></a>&nbsp;
+        <a href="{{ url_for('.user_forward', user_email=user.address) }}" title="Auto-forward"><i class="fa fa-share"></i></a>&nbsp;
+        <a href="{{ url_for('.user_reply', user_email=user.address) }}" title="Auto-reply"><i class="fa fa-plane"></i></a>&nbsp;
+        <a href="{{ url_for('.user_fetchmail', user_email=user.address) }}" title="Fetched accounts"><i class="fa fa-download"></i></a>&nbsp;
       </td>
       <td>{{ user }}</td>
       <td>
diff --git a/dovecot/conf/dovecot-sql.conf.ext b/dovecot/conf/dovecot-sql.conf.ext
index c590b195..7cb60250 100644
--- a/dovecot/conf/dovecot-sql.conf.ext
+++ b/dovecot/conf/dovecot-sql.conf.ext
@@ -5,12 +5,10 @@ connect = /data/freeposte.db
 password_query = \
  SELECT password \
    FROM user \
-  WHERE user.domain_name = '%d' \
-    AND user.localpart = '%n'
+  WHERE user.address = '%u'
 
 # Mostly get the user quota
 user_query = \
  SELECT '*:bytes=' || user.quota_bytes AS quota_rule \
    FROM user \
-  WHERE user.domain_name = '%d' \
-    AND user.localpart = '%n'
+  WHERE user.address = '%u'
diff --git a/postfix/conf/sqlite-virtual_alias_maps.cf b/postfix/conf/sqlite-virtual_alias_maps.cf
index 7c7f28f6..979133ff 100644
--- a/postfix/conf/sqlite-virtual_alias_maps.cf
+++ b/postfix/conf/sqlite-virtual_alias_maps.cf
@@ -2,5 +2,4 @@ dbpath = /data/freeposte.db
 query =
  SELECT destination
    FROM alias
-  WHERE alias.domain_name = '%d'
-    AND alias.localpart = '%u'
+  WHERE alias.address = '%s'