diff --git a/seed/dovecot/templates/dovecot-ldap.conf.ext b/seed/dovecot/templates/dovecot-ldap.conf.ext
index 168da383..3162b2d5 100644
--- a/seed/dovecot/templates/dovecot-ldap.conf.ext
+++ b/seed/dovecot/templates/dovecot-ldap.conf.ext
@@ -136,7 +136,7 @@ user_attrs = homeDirectory=home
 #   %d - domain part in user@domain, empty if user there's no domain
 #user_filter = (&(objectClass=posixAccount)(uid=%u))
 #>GNUNUX
-user_filter = (&(objectClass=inetOrgPerson)(mail=%u))
+user_filter = (&(objectClass=inetOrgPerson)(mailLocalAddress=%u))
 #<GNUNUX
 
 # Password checking attributes:
diff --git a/seed/dovecot/templates/imap.yml b/seed/dovecot/templates/imap.yml
index d5ef2bf4..82233af3 100644
--- a/seed/dovecot/templates/imap.yml
+++ b/seed/dovecot/templates/imap.yml
@@ -8,3 +8,5 @@ password: %%get_password(server_name='test', username=%%username, description="t
 username_family: %%username_family
 password_family: %%get_password(server_name='test', username=%%username_family, description='test', type="cleartext", hide=%%hide_secret, temporary=True)
 name_family: %%name_family
+smtp: %%get_ip(%%smtp_relay_address)
+ext_username: 'test@example.net'
diff --git a/seed/dovecot/tests/test_imap.py b/seed/dovecot/tests/test_imap.py
index 9fb425b6..d5638ff0 100644
--- a/seed/dovecot/tests/test_imap.py
+++ b/seed/dovecot/tests/test_imap.py
@@ -1,6 +1,7 @@
 from yaml import load, SafeLoader
 from os import environ
 import pytest
+import datetime
 
 from imaplib2 import IMAP4_SSL
 from smtplib import SMTP, SMTPNotSupportedError, SMTPAuthenticationError
@@ -10,17 +11,29 @@ from smtplib import SMTP, SMTPNotSupportedError, SMTPAuthenticationError
 conf_file = f'{environ["MACHINE_TEST_DIR"]}/imap.yml'
 with open(conf_file) as yaml:
     data = load(yaml, Loader=SafeLoader)
-parameters = (('user', data['username'], [data['password']]),
-              ('family', data['username_family'], [data['password_family'], data['password_family'] + "2"]),
+parameters = (
+              (1, 5, 'user', data['username'], data['username'], data['username'], [data['password']]),
+              (2, 5, 'user', data['username'], data['username'], 'alias_' + data['username'], [data['password']]),
+              (1, 3, 'family', data['username_family'], data['username_family'], data['username_family'], [data['password_family'], data['password_family'] + "2"]),
+              (3, 5, 'user', data['username'], data['ext_username'], data['username'], [data['password']]),
+             (4, 5, 'user', data['username'], data['ext_username'], 'alias_' + data['username'], [data['password']]),
+              (2, 3, 'family', data['username_family'], data['ext_username'], data['username_family'], [data['password_family'], data['password_family'] + "2"]),
               )
 
 
-def get_msg(username, msg='MESSAGE'):
-    return f'From: {username}\r\nTo: {username}\r\n\r\nSubject: TEST\r\n{msg}\r\n'
+def get_msg(username, dest, msg='MESSAGE', with_date=True):
+    date = datetime.datetime.now()
+    ret = f'From: {username}\r\nTo: {dest}\r\n\r\nSubject: TEST\r\n{msg}\r\n'
+    if with_date:
+        date_str = date.strftime('%a, %d %b %Y %H:%M:%S +0200 (CEST)')
+        ret = f'Date: {date_str}\r\n{ret}'
+    return ret
 
 
-@pytest.mark.parametrize('typ, username, passwords', parameters)
-def test_imap_wrong_password(typ, username, passwords):
+@pytest.mark.parametrize('idx, maxi, typ, login_username, username, dest, passwords', parameters)
+def test_imap_wrong_password(idx, maxi, typ, login_username, username, dest, passwords):
+    if username == data['ext_username']:
+        return
     imap = IMAP4_SSL(data['address'])
     try:
         imap.LOGIN(username, 'b')
@@ -30,9 +43,13 @@ def test_imap_wrong_password(typ, username, passwords):
         raise Exception('wrong login !')
 
 
-@pytest.mark.parametrize('typ, username, passwords', parameters)
-def test_imap_migration(typ, username, passwords):
-    msg = get_msg(username, 'MIGRATION')
+@pytest.mark.parametrize('idx, maxi, typ, login_username, username, dest, passwords', parameters)
+def test_imap_migration(idx, maxi, typ, login_username, username, dest, passwords):
+    if dest.startswith('alias_'):
+        return
+    if username == data['ext_username']:
+        return
+    msg = get_msg(username, dest, 'MIGRATION', False)
     if 'FIRST_RUN' in environ:
         smtp = SMTP(data['address'], '587')
         smtp.starttls()
@@ -45,7 +62,7 @@ def test_imap_migration(typ, username, passwords):
                 error = err
         else:
             raise error from error
-        smtp.sendmail(username, username, msg)
+        smtp.sendmail(username, dest, msg)
         smtp.quit()
     imap = IMAP4_SSL(data['address'])
     error = None
@@ -69,15 +86,19 @@ def test_imap_migration(typ, username, passwords):
     imap.LOGOUT()
 
 
-@pytest.mark.parametrize('typ, username, passwords', parameters)
-def test_smtp_no_tls(typ, username, passwords):
+@pytest.mark.parametrize('idx, maxi, typ, login_username, username, dest, passwords', parameters)
+def test_smtp_no_tls(idx, maxi, typ, login_username, username, dest, passwords):
+    if username == data['ext_username']:
+        return
     smtp = SMTP(data['address'], '587')
     with pytest.raises(SMTPNotSupportedError):
         smtp.login(username, passwords[0])
 
 
-@pytest.mark.parametrize('typ, username, passwords', parameters)
-def test_smtp_wrong_passwd(typ, username, passwords):
+@pytest.mark.parametrize('idx, maxi, typ, login_username, username, dest, passwords', parameters)
+def test_smtp_wrong_passwd(idx, maxi, typ, login_username, username, dest, passwords):
+    if username == data['ext_username']:
+        return
     smtp = SMTP(data['address'], '587')
     smtp.starttls()
     with pytest.raises(SMTPAuthenticationError):
@@ -85,8 +106,10 @@ def test_smtp_wrong_passwd(typ, username, passwords):
     smtp.quit()
 
 
-@pytest.mark.parametrize('typ, username, passwords', parameters)
-def test_smtp_login(typ, username, passwords):
+@pytest.mark.parametrize('idx, maxi, typ, login_username, username, dest, passwords', parameters)
+def test_smtp_login(idx, maxi, typ, login_username, username, dest, passwords):
+    if username == data['ext_username']:
+        return
     smtp = SMTP(data['address'], '587')
     smtp.starttls()
     error = None
@@ -101,30 +124,33 @@ def test_smtp_login(typ, username, passwords):
     smtp.quit()
 
 
-@pytest.mark.parametrize('typ, username, passwords', parameters)
-def test_smtp_sendmail(typ, username, passwords):
-    smtp = SMTP(data['address'], '587')
-    smtp.starttls()
-    error = None
-    for password in passwords:
-        try:
-            smtp.login(username, password)
-            break
-        except SMTPAuthenticationError as err:
-            error = err
+@pytest.mark.parametrize('idx, maxi, typ, login_username, username, dest, passwords', parameters)
+def test_smtp_sendmail(idx, maxi, typ, login_username, username, dest, passwords):
+    if username == data['ext_username']:
+        smtp = SMTP(data['smtp'], '25')
     else:
-        raise error from error
-    smtp.sendmail(username, username, get_msg(username))
+        smtp = SMTP(data['address'], '587')
+        smtp.starttls()
+        error = None
+        for password in passwords:
+            try:
+                smtp.login(username, password)
+                break
+            except SMTPAuthenticationError as err:
+                error = err
+        else:
+            raise error from error
+    smtp.sendmail(username, dest, get_msg(username, dest))
     smtp.quit()
 
 
-@pytest.mark.parametrize('typ, username, passwords', parameters)
-def test_imap_read_mail(typ, username, passwords):
+@pytest.mark.parametrize('idx, maxi, typ, login_username, username, dest, passwords', parameters)
+def test_imap_read_mail(idx, maxi, typ, login_username, username, dest, passwords):
     imap = IMAP4_SSL(data['address'])
     error = None
     for password in passwords:
         try:
-            imap.LOGIN(username, password)
+            imap.LOGIN(login_username, password)
             break
         except Exception as err:
             error = err
@@ -134,24 +160,31 @@ def test_imap_read_mail(typ, username, passwords):
     typ, req = imap.SEARCH(None, 'ALL')
     assert typ == 'OK'
     assert len(req) == 1
-    msg = get_msg(username)
+    msg = get_msg(username, dest, with_date=False)
     msg_no = req[0].split()
-    assert len(msg_no) == 2
-    for num in msg_no[1:]:
-        field = imap.FETCH(num, '(RFC822)')
-        assert field[0] == 'OK'
-        assert field[1][-2][-1].decode().endswith(msg)
+    assert len(msg_no) == maxi
+    num = msg_no[idx]
+    field = imap.FETCH(num, '(RFC822)')
+    assert field[0] == 'OK'
+    fdata = field[1][-2][-1].decode().split('\r\n')
+    if fdata[-2].startswith('--'):
+        fdata = fdata[:-2]
+    fdata = '\r\n'.join(fdata)
+    assert 'Undelivered' not in fdata
+    assert fdata.endswith(msg)
     imap.CLOSE()
     imap.LOGOUT()
 
 
-@pytest.mark.parametrize('typ, username, passwords', parameters)
-def test_imap_delete_mail(typ, username, passwords):
+@pytest.mark.parametrize('idx, maxi, typ, login_username, username, dest, passwords', parameters)
+def test_imap_delete_mail(idx, maxi, typ, login_username, username, dest, passwords):
+    if username == data['ext_username']:
+        return
     imap = IMAP4_SSL(data['address'])
     error = None
     for password in passwords:
         try:
-            imap.LOGIN(username, password)
+            imap.LOGIN(login_username, password)
             break
         except Exception as err:
             error = err