diff --git a/emails/backend/smtp/backend.py b/emails/backend/smtp/backend.py
index 558e75d..56ed3e6 100644
--- a/emails/backend/smtp/backend.py
+++ b/emails/backend/smtp/backend.py
@@ -26,7 +26,7 @@ class SMTPBackend(object):
     connection_ssl_cls = SMTPClientWithResponse_SSL
     response_cls = SMTPResponse
 
-    def __init__(self, ssl=False, fail_silently=True, **kwargs):
+    def __init__(self, ssl=False, fail_silently=True, mail_options=None, **kwargs):
 
         self.smtp_cls = ssl and self.connection_ssl_cls or self.connection_cls
 
@@ -46,6 +46,7 @@ class SMTPBackend(object):
         self.host = kwargs.get('host')
         self.port = kwargs.get('port')
         self.fail_silently = fail_silently
+        self.mail_options = mail_options or []
 
         self._client = None
 
@@ -119,7 +120,7 @@ class SMTPBackend(object):
         response = send(from_addr=from_addr,
                         to_addrs=to_addrs,
                         msg=msg.as_string(),
-                        mail_options=mail_options,
+                        mail_options=mail_options or self.mail_options,
                         rcpt_options=rcpt_options)
 
         if not self.fail_silently:
diff --git a/emails/compat/__init__.py b/emails/compat/__init__.py
index 9f301e1..d4a10f8 100644
--- a/emails/compat/__init__.py
+++ b/emails/compat/__init__.py
@@ -160,7 +160,10 @@ elif is_py3:
         Does not encode non-ascii realname.
 
         Python3 email.utils.formataddr do encode realname.
+
+        TODO: switch to email.headerregistry.AddressHeader ?
         """
+
         name, address = pair
         if name:
             quotes = ''
diff --git a/emails/utils.py b/emails/utils.py
index 46a5abd..cb90a78 100644
--- a/emails/utils.py
+++ b/emails/utils.py
@@ -12,7 +12,8 @@ from email import generator
 from email.mime.text import MIMEText
 from email.mime.multipart import MIMEMultipart
 from email.header import Header, decode_header as decode_header_
-from email.utils import formataddr, parseaddr, formatdate
+from email.utils import parseaddr, formatdate
+from emails.compat import formataddr
 
 import requests
 

diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index e508d08..871bb40 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -22,7 +22,7 @@ jobs:
           - {name: '2.7', python: '2.7', os: ubuntu-16.04, tox: py27}
     services:
       postfix:
-        image: juanluisbaptiste/postfix
+        image: lavr/docker-postfix
         env:
           SMTP_SERVER: smtp.gmail.com
           SMTP_PORT: 587
@@ -53,11 +53,13 @@ jobs:
       - name: run rests
         env:
           SMTP_TEST_SUBJECT_SUFFIX: "github-actions sha:${{ github.sha }} run_id:${{ github.run_id }}"
+          SMTP_TEST_MAIL_FROM: python-emails-tests@lavr.me
+          SMTP_TEST_MAIL_TO: python-emails-tests@lavr.me
           SMTP_TEST_SETS: LOCAL
-          SMTP_TEST_LOCAL_TO: python-emails-tests@lavr.me
           SMTP_TEST_LOCAL_WITHOUT_TLS: true
           SMTP_TEST_LOCAL_HOST: 127.0.0.1
           SMTP_TEST_LOCAL_PORT: 2525
+
           SMTP_TEST_GMAIL_TO: python-emails-tests@lavr.me
           SMTP_TEST_GMAIL_USER: ${{ secrets.SMTP_TEST_GMAIL_USER }}
           SMTP_TEST_GMAIL_PASSWORD: ${{ secrets.SMTP_TEST_GMAIL_PASSWORD }}
diff --git a/emails/testsuite/message/helpers.py b/emails/testsuite/message/helpers.py
index 6fe2144..9050bce 100644
--- a/emails/testsuite/message/helpers.py
+++ b/emails/testsuite/message/helpers.py
@@ -5,10 +5,11 @@ import os
 import emails
 from emails.template import JinjaTemplate
 
-TO_EMAIL = os.environ.get('TEST_TO_EMAIL') or 'python.emails.test.2@yandex.ru'
-FROM_EMAIL = os.environ.get('TEST_FROM_EMAIL') or 'python-emails@lavr.me'
+TO_EMAIL = os.environ.get('SMTP_TEST_MAIL_TO') or 'python.emails.test.2@yandex.ru'
+FROM_EMAIL = os.environ.get('SMTP_TEST_MAIL_FROM') or 'python-emails@lavr.me'
 ROOT = os.path.dirname(__file__)
 
+
 def common_email_data(**kw):
     T = JinjaTemplate
     data = {'charset': 'utf-8',
diff --git a/emails/testsuite/message/test_message.py b/emails/testsuite/message/test_message.py
index 55a838d..51fead3 100644
--- a/emails/testsuite/message/test_message.py
+++ b/emails/testsuite/message/test_message.py
@@ -147,6 +147,13 @@ def test_message_addresses():
     assert m.mail_to == [("웃", "b@c.d"), (None, "e@f.g")]
 
 
+def test_rfc6532_address():
+    m = Message()
+    m.mail_to = "anaïs@example.com"
+    m.html = 'X'
+    assert m.as_string()
+
+
 def test_message_policy():
 
     if is_py34_plus:
diff --git a/emails/testsuite/message/test_send.py b/emails/testsuite/message/test_send.py
index 2493211..d3be34b 100644
--- a/emails/testsuite/message/test_send.py
+++ b/emails/testsuite/message/test_send.py
@@ -26,6 +26,9 @@ def get_letters():
     del data['html']
     yield emails.loader.from_url(url=url, message_params=data, images_inline=True), None
 
+    # Email with utf-8 "to"
+    yield emails.Message(**common_email_data(mail_to="anaïs@lavr.me", subject="UTF-8 To")), None
+
 
 def test_send_letters():
 
@@ -33,10 +36,9 @@ def test_send_letters():
         for tag, server in get_servers():
             server.patch_message(m)
             print(tag, server.params)
-            response = m.send(smtp=server.params, render=render)
-            print(server.params)
-            assert response.success or response.status_code in (421, 451)  # gmail not always like test emails
-            server.sleep()
+            response = m.send(smtp=server.params, render=render, smtp_mail_options=['smtputf8'])
+            assert response.success
+            # server.sleep()
 
 
 def test_send_with_context_manager():
diff --git a/emails/testsuite/smtp_servers.py b/emails/testsuite/smtp_servers.py
index ba6e981..4b0afd2 100644
--- a/emails/testsuite/smtp_servers.py
+++ b/emails/testsuite/smtp_servers.py
@@ -41,7 +41,7 @@ def smtp_server_from_env(name='GMAIL'):
         return v
 
     def _valid_smtp(data):
-        return data['to_email'] and data['host']
+        return data['host']
 
     smtp_info = dict(
         from_email=_var("FROM", default=DEFAULT_FROM),

Library does not support RFC 6532 (non ascii characters in local part of the email address)
The `sanitize_address` function in the utils file imports and makes use of the `formataddr` function from the stdlib.

According to [this thread ](https://bugs.python.org/issue25955), the `formataddr` should no longer be used:

> formataddr is part of the legacy interface and has no knowledge of the current policy.  So it doesn't support RFC 6532.  For that you need to use the new API: just assign your address to the appropriate field, or create a headerregistry.Address object.

Because of this, it is impossible to send emails to addresses such as **`anaïs@example.com`** with this package, although it should be possible to send an email to such an address using a smtp server supporting SMTPUTF8. (At least according to [RFC 6532](https://tools.ietf.org/html/rfc6532))






emails/testsuite/message/test_message.py::test_rfc6532_address
emails/testsuite/message/test_message.py::test_date emails/testsuite/message/test_message.py::test_sanitize_header emails/testsuite/message/test_message.py::test_headers_not_double_encoded emails/testsuite/message/test_message.py::test_headers_ascii_encoded emails/testsuite/message/test_message.py::test_message_addresses emails/testsuite/message/test_message.py::test_message_id emails/testsuite/message/test_message.py::test_several_recipients emails/testsuite/message/test_message.py::test_transform emails/testsuite/message/test_send.py::test_send_with_context_manager