test: report if rate limit from last test was still active

chatmaild/src/chatmaild/dictproxy.py

@@ -31,9 +31,7 @@ def encrypt_password(password: str):
 
 def create_user(db, user, password):
     if os.path.exists(NOCREATE_FILE):
-        logging.warning(
+        logging.warning(f"Didn't create account: {NOCREATE_FILE} exists. Delete the file to enable account creation.")
-            f"Didn't create account: {NOCREATE_FILE} exists. Delete the file to enable account creation."
-        )
         return
     with db.write_transaction() as conn:
         conn.create_user(user, password)
@@ -61,7 +59,7 @@ def lookup_passdb(db, user, password):
     return userdata
 
 
-def handle_dovecot_request(msg, db, mail_domain):
+def handle_dovecot_request(msg, db):
     print(f"received msg: {msg!r}", file=sys.stderr)
     short_command = msg[0]
     if short_command == "L":  # LOOKUP
@@ -72,15 +70,13 @@ def handle_dovecot_request(msg, db, mail_domain):
         res = ""
         if namespace == "shared":
             if type == "userdb":
-                if user.endswith(f"@{mail_domain}"):
+                res = lookup_userdb(db, user)
-                    res = lookup_userdb(db, user)
                 if res:
                     reply_command = "O"
                 else:
                     reply_command = "N"
             elif type == "passdb":
-                if user.endswith(f"@{mail_domain}"):
+                res = lookup_passdb(db, user, password=args[0])
-                    res = lookup_passdb(db, user, password=args[0])
                 if res:
                     reply_command = "O"
                 else:
@@ -99,8 +95,6 @@ def main():
     socket = sys.argv[1]
     passwd_entry = pwd.getpwnam(sys.argv[2])
     db = Database(sys.argv[3])
-    with open("/etc/mailname", "r") as fp:
-        mail_domain = fp.read().strip()
 
     class Handler(StreamRequestHandler):
         def handle(self):
@@ -108,7 +102,7 @@ def main():
                 msg = self.rfile.readline().strip().decode()
                 if not msg:
                     break
-                res = handle_dovecot_request(msg, db, mail_domain)
+                res = handle_dovecot_request(msg, db)
                 if res:
                     print(f"sending result: {res!r}", file=sys.stderr)
                     self.wfile.write(res.encode("ascii"))

chatmaild/src/chatmaild/filtermail.py

@@ -3,7 +3,6 @@ import asyncio
 import logging
 from email.parser import BytesParser
 from email import policy
-from email.utils import parseaddr
 
 from aiosmtpd.lmtp import LMTP
 from aiosmtpd.controller import UnixSocketController
@@ -43,14 +42,50 @@ class ExampleHandler:
         return "250 OK"
 
     async def handle_DATA(self, server, session, envelope):
-        valid_recipients, res = lmtp_handle_DATA(envelope)
+        logging.info("Processing DATA message from %s", envelope.mail_from)
+
+        valid_recipients = []
+
+        message = BytesParser(policy=policy.default).parsebytes(envelope.content)
+        mail_encrypted = check_encrypted(message)
+
+        res = []
+        for recipient in envelope.rcpt_tos:
+            my_local_domain = envelope.mail_from.split("@")
+            if len(my_local_domain) != 2:
+                res += [f"500 Invalid from address <{envelope.mail_from}>"]
+                continue
+
+            if envelope.mail_from == recipient:
+                # Always allow sending emails to self.
+                valid_recipients += [recipient]
+                res += ["250 OK"]
+                continue
+
+            recipient_local_domain = recipient.split("@")
+            if len(recipient_local_domain) != 2:
+                res += [f"500 Invalid address <{recipient}>"]
+                continue
+
+            is_outgoing = recipient_local_domain[1] != my_local_domain[1]
+
+            if (
+                is_outgoing
+                and not mail_encrypted
+                and message.get("secure-join") != "vc-request"
+                and message.get("secure-join") != "vg-request"
+            ):
+                res += ["500 Outgoing mail must be encrypted"]
+                continue
+
+            valid_recipients += [recipient]
+            res += ["250 OK"]
+
         # Reinject the mail back into Postfix.
         if valid_recipients:
             logging.info("Reinjecting the mail")
             client = SMTPClient("localhost", "10026")
             client.sendmail(envelope.mail_from, valid_recipients, envelope.content)
-        else:
-            logging.info("no valid recipients, ignoring mail")
 
         return "\r\n".join(res)
 
@@ -62,57 +97,6 @@ async def asyncmain(loop):
     controller.start()
 
 
-def lmtp_handle_DATA(envelope):
-    """the central filtering function for e-mails."""
-    logging.info(f"Processing DATA message from {envelope.mail_from}")
-
-    message = BytesParser(policy=policy.default).parsebytes(envelope.content)
-    mail_encrypted = check_encrypted(message)
-
-    valid_recipients = []
-    res = []
-    for recipient in envelope.rcpt_tos:
-        my_local_domain = envelope.mail_from.split("@")
-        if len(my_local_domain) != 2:
-            res += [f"500 Invalid from address <{envelope.mail_from}>"]
-            continue
-
-        _, from_addr = parseaddr(message.get("from").strip())
-        logging.info(f"mime-from: {from_addr} envelope-from: {envelope.mail_from}")
-        if envelope.mail_from.lower() != from_addr.lower():
-            res += [f"500 Invalid FROM <{from_addr}> for <{envelope.mail_from}>"]
-            continue
-
-        if envelope.mail_from == recipient:
-            # Always allow sending emails to self.
-            valid_recipients += [recipient]
-            res += ["250 OK"]
-            continue
-
-        recipient_local_domain = recipient.split("@")
-        if len(recipient_local_domain) != 2:
-            res += [f"500 Invalid address <{recipient}>"]
-            continue
-
-        is_outgoing = recipient_local_domain[1] != my_local_domain[1]
-
-        if (
-            is_outgoing
-            and not mail_encrypted
-            and message.get("secure-join") != "vc-request"
-            and message.get("secure-join") != "vg-request"
-        ):
-            res += ["500 Outgoing mail must be encrypted"]
-            continue
-
-        valid_recipients += [recipient]
-        res += ["250 OK"]
-
-    assert len(envelope.rcpt_tos) == len(res)
-    assert len(valid_recipients) <= len(res)
-    return valid_recipients, res
-
-
 def main():
     logging.basicConfig(level=logging.INFO)
     loop = asyncio.new_event_loop()

chatmaild/src/chatmaild/test_filtermail.py

@@ -1,46 +1,8 @@
-from .filtermail import check_encrypted, lmtp_handle_DATA
+from .filtermail import check_encrypted
 from email.parser import BytesParser
 from email import policy
 
 
-def test_reject_forged_from():
-    def makemail(from_addr):
-        return BytesParser(policy=policy.default).parsebytes(
-            "\r\n".join(
-                [
-                    f"From: <{from_addr}",
-                    "To: <barbaz@c3.testrun.org>",
-                    "Date: Sun, 15 Oct 2023 16:41:44 +0000",
-                    "Message-ID: <Mr.3gckbNy5bch.uK3Hd2Ws6-w@c2.testrun.org>",
-                    "References: <Mr.3gckbNy5bch.uK3Hd2Ws6-w@c2.testrun.org>",
-                    "Chat-Version: 1.0",
-                    "MIME-Version: 1.0",
-                    "Content-Type: text/plain; charset=utf-8; format=flowed; delsp=no",
-                    "",
-                    "Hi!",
-                    "",
-                    "",
-                ]
-            ).encode()
-        )
-
-    class envelope:
-        mail_from = "bob@c3.testrun.org"
-        rcpt_tos = ["somebody@c3.testrun.org"]
-
-    # test that the filter lets good mail through
-    envelope.content = makemail(envelope.mail_from).as_bytes()
-    valid_recipients, res = lmtp_handle_DATA(envelope=envelope)
-    assert valid_recipients == envelope.rcpt_tos
-    assert len(res) == 1 and "250" in res[0]
-
-    # test that the filter rejects forged mail
-    envelope.content = makemail("forged@c3.testrun.org").as_bytes()
-    valid_recipients, res = lmtp_handle_DATA(envelope=envelope)
-    assert not valid_recipients
-    assert len(res) == 1 and "500" in res[0]
-
-
 def test_filtermail():
     def check_encrypted_bstr(content):
         message = BytesParser(policy=policy.default).parsebytes(content)

deploy-chatmail/src/deploy_chatmail/__init__.py

@@ -244,13 +244,6 @@ def deploy_chatmail(mail_domain: str, mail_server: str, dkim_selector: str) -> N
         restarted=dovecot_need_restart,
     )
 
-    # This file is used by auth proxy.
-    # https://wiki.debian.org/EtcMailName
-    server.shell(
-        name="Setup /etc/mailname",
-        commands=[f"echo {mail_domain} >/etc/mailname; chmod 644 /etc/mailname"],
-    )
-
     def callback():
         result = server.shell(
             commands=[

deploy-chatmail/src/deploy_chatmail/postfix/main.cf.j2

@@ -29,6 +29,9 @@ myhostname = {{ config.domain_name }}
 alias_maps = hash:/etc/aliases
 alias_database = hash:/etc/aliases
 
+# hard limit, also on internal messages
+smtpd_client_message_rate_limit = 80
+
 # Postfix does not deliver mail for any domain by itself.
 # Primary domain is listed in `virtual_mailbox_domains` instead
 # and handed over to Dovecot.

online-tests/conftest.py

@@ -75,24 +75,6 @@ class ImapConn:
         print(f"imap-login {user!r} {password!r}")
         self.conn.login(user, password)
 
-    def fetch_all(self):
-        print("imap-fetch all")
-        status, res = self.conn.select()
-        if int(res[0]) == 0:
-            raise ValueError("no messages in imap folder")
-        status, results = self.conn.fetch("1:*", "(RFC822)")
-        assert status == "OK"
-        return results
-
-    def fetch_all_messages(self):
-        print("imap-fetch all messages")
-        results = self.fetch_all()
-        messages = []
-        for item in results:
-            if len(item) == 2:
-                messages.append(item[1].decode())
-        return messages
-
 
 @pytest.fixture
 def smtp(maildomain):
@@ -115,11 +97,6 @@ class SmtpConn:
         print(f"smtp-login {user!r} {password!r}")
         self.conn.login(user, password)
 
-    def sendmail(self, from_addr, to_addrs, msg):
-        print(f"smtp-sendmail from={from_addr!r} to_addrs={to_addrs!r}")
-        print(f"smtp-sendmail message size: {len(msg)}")
-        return self.conn.sendmail(from_addr=from_addr, to_addrs=to_addrs, msg=msg)
-
 
 @pytest.fixture(params=["imap", "smtp"])
 def imap_or_smtp(request):
@@ -221,66 +198,4 @@ class Remote:
         )
         while 1:
             line = self.popen.stdout.readline()
-            res = line.decode().strip().lower()
+            yield line.decode().strip().lower()
-            if res:
-                yield res
-            else:
-                break
-
-
-@pytest.fixture
-def mailgen(request):
-    class Mailgen:
-        def get_encrypted(self, from_addr, to_addr):
-            data = request.fspath.dirpath("mailgen/encrypted.eml").read()
-            return data.format(from_addr=from_addr, to_addr=to_addr)
-
-    return Mailgen()
-
-
-@pytest.fixture
-def cmsetup(maildomain, gencreds):
-    return CMSetup(maildomain, gencreds)
-
-
-class CMSetup:
-    def __init__(self, maildomain, gencreds):
-        self.maildomain = maildomain
-        self.gencreds = gencreds
-
-    def gen_users(self, num):
-        print(f"Creating {num} online users")
-        users = []
-        for i in range(num):
-            addr, password = self.gencreds()
-            user = CMUser(self.maildomain, addr, password)
-            assert user.smtp
-            users.append(user)
-        return users
-
-
-class CMUser:
-    def __init__(self, maildomain, addr, password):
-        self.maildomain = maildomain
-        self.addr = addr
-        self.password = password
-        self._smtp = None
-        self._imap = None
-
-    @property
-    def smtp(self):
-        if not self._smtp:
-            handle = SmtpConn(self.maildomain)
-            handle.connect()
-            handle.login(self.addr, self.password)
-            self._smtp = handle
-        return self._smtp
-
-    @property
-    def imap(self):
-        if not self._imap:
-            imap = ImapConn(self.maildomain)
-            imap.connect()
-            imap.login(self.addr, self.password)
-            self._imap = imap
-        return self._imap

online-tests/mailgen/encrypted.eml

@@ -1,66 +0,0 @@
-From: {from_addr}
-To: {to_addr}
-Subject: ...
-Date: Sun, 15 Oct 2023 16:43:21 +0000
-Message-ID: <Mr.UVyJWZmkCKM.hGzNc6glBE_@c2.testrun.org>
-In-Reply-To: <Mr.MvmCz-GQbi_.6FGRkhDf05c@c2.testrun.org>
-References: <Mr.3gckbNy5bch.uK3Hd2Ws6-w@c2.testrun.org>
-	<Mr.MvmCz-GQbi_.6FGRkhDf05c@c2.testrun.org>
-Chat-Version: 1.0
-Autocrypt: addr={from_addr}; prefer-encrypt=mutual;
-	keydata=xjMEZSwWjhYJKwYBBAHaRw8BAQdAQBEhqeJh0GueHB6kF/DUQqYCxARNBVokg/AzT+7LqH
-	rNFzxiYXJiYXpAYzIudGVzdHJ1bi5vcmc+wosEEBYIADMCGQEFAmUsFo4CGwMECwkIBwYVCAkKCwID
-	FgIBFiEEFTfUNvVnY3b9F7yHnmme1PfUhX8ACgkQnmme1PfUhX9A4AEAnHWHp49eBCMHK5t66gYPiW
-	XQuB1mwUjzGfYWB+0RXUoA/0xcQ3FbUNlGKW7Blp6eMFfViv6Mv2d3kNSXACB6nmcMzjgEZSwWjhIK
-	KwYBBAGXVQEFAQEHQBpY5L2M1XHo0uxf8SX1wNLBp/OVvidoWHQF2Jz+kJsUAwEIB8J4BBgWCAAgBQ
-	JlLBaOAhsMFiEEFTfUNvVnY3b9F7yHnmme1PfUhX8ACgkQnmme1PfUhX/INgEA37AJaNvruYsJVanP
-	IXnYw4CKd55UAwl8Zcy+M2diAbkA/0fHHcGV4r78hpbbL1Os52DPOdqYQRauIeJUeG+G6bQO
-MIME-Version: 1.0
-Content-Type: multipart/encrypted; protocol="application/pgp-encrypted";
-	boundary="YFrteb74qSXmggbOxZL9dRnhymywAi"
-
-
---YFrteb74qSXmggbOxZL9dRnhymywAi
-Content-Description: PGP/MIME version identification
-Content-Type: application/pgp-encrypted
-
-Version: 1
-
-
---YFrteb74qSXmggbOxZL9dRnhymywAi
-Content-Description: OpenPGP encrypted message
-Content-Disposition: inline; filename="encrypted.asc";
-Content-Type: application/octet-stream; name="encrypted.asc"
-
------BEGIN PGP MESSAGE-----
-
-wU4DhW3gBZ/VvCYSAQdA8bMs2spwbKdGjVsL1ByPkNrqD7frpB73maeL6I6SzDYg
-O5G53tv339RdKq3WRcCtEEvxjHlUx2XNwXzC04BpmfvBTgNfPUyLDzjXnxIBB0Ae
-8ymwGvXMCCimHXN0Dg8Ui62KOi03h0UgheoHWovJSCDF4CKre/xtFr3nL7lq/PKI
-JsjVNz7/RK9FSXF6WwfONtLCyQGEuVAsB/KXfCBEyfKhaMwGHvhujRidGW5uV1no
-lMGl3ODmo29Lgeu2uSE7EpJRZoe6hU6ddmBkqxax61ZtkaFlGFFpdo2K8balNNdz
-ZsJ/9mmI9x3oOJ4/l1nhQbUO9ADbs7gJhFdV5Qkp30b5fCI7bU+aoe1ccBbLe/WM
-YUty1PqcuQT7XjA+XmYuL261tvW8pBetT+i33/E2d8PzzYt2IuK9qeevyS+yxdwA
-kfwejFWzzsUlJaDxs1x4XOxkMgSj+jo+g12dFOb7fyClsAnq23iDb8AuaT/BScAI
-+lO+gher69+6LmM7VGHLG5k762J1jTaQCaKt1s8TAWV99Eo4491vL6fyvk3l/Cfg
-RXSwiWFgj19Pn0Rq7CD9v22UE2vdUMBTcV4aw79mClk1YQ23jbF0y5DCjPdJ62Zo
-tskBgFt3NoWV80jZ76zIBLrrjLwCCll8JjJtFwSkt2GX5RFBsVa4A8IDht9RtEk7
-rrHgbSZQfkauEi/mH3/6CDZoLqSHudUZ7d4MaJwun1TkFYGe2ORwGJd4OBj3oGJp
-H8YBwCpk///L/fKjX0Gg3M8nrpM4wrRFhPKidAgO/kcm25X4+ZHlVkWBTCt5RWKI
-fHh6oLDZCqCfcgMkE1KKmwfIHaUkhq5BPRigwy6i5dh1DM4+1UCLh3dxzVbqE9b9
-61NB19nXdRtDA2sOUnj9ve6m/wEPyCb6/zBQZqvCBYb1/AjdXpUrFT+DbpfyxaXN
-XfhDVb5mNqNM/IVj0V5fvTc6vOfYbzQtPm10H+FdWWfb+rJRfyC3MA2w2IqstFe3
-w3bu2iE6CQvSqRvge+ZqLKt/NqYwOURiUmpuklbl3kPJ97+mfKWoiqk8Iz1VY+bb
-NMUC7aoGv+jcoj+WS6PYO8N6BeRVUUB3ZJSf8nzjgxm1/BcM+UD3BPrlhT11ODRs
-baifGbprMWwt3dhb8cQgRT8GPdpO1OsDkzL6iikMjLHWWiA99GV6ruiHsIPw6boW
-A6/uSOskbDHOROotKmddGTBd0iiHXAoQsJFt1ZjUkt6EHrgWs+GAvrvKpXs1mrz8
-uj3GwEFrHS+Xuf2UDgpszYT3hI2cL/kUtGakVR7m7vVMZqXBUbZdGAEb1PZNPwsI
-E4aMK02+EVB+tSN4Fzj99N2YD0inVYt+oPjr2tHhUS6aSGBNS/48Ki47DOg4Sxkn
-lkOWnEbCD+XTnbDd
-=agR5
------END PGP MESSAGE-----
-
-
---YFrteb74qSXmggbOxZL9dRnhymywAi--
-
-

online-tests/test_0_basic.py

@@ -1,7 +1,3 @@
-import smtplib
-import pytest
-
-
 def test_remote(remote, imap_or_smtp):
     lineproducer = remote.iter_output(imap_or_smtp.logcmd)
     imap_or_smtp.connect()
@@ -17,36 +13,3 @@ def test_use_two_chatmailservers(cmfactory, maildomain2):
     domain1 = ac1.get_config("addr").split("@")[1]
     domain2 = ac2.get_config("addr").split("@")[1]
     assert domain1 != domain2
-
-
-@pytest.mark.parametrize("forgeaddr", ["internal", "someone@example.org"])
-def test_reject_forged_from(cmsetup, mailgen, lp, remote, forgeaddr):
-    user1, user3 = cmsetup.gen_users(2)
-
-    lp.sec("send encrypted message with forged from")
-    print("envelope_from", user1.addr)
-    if forgeaddr == "internal":
-        addr_to_forge = cmsetup.gen_users(1)[0].addr
-    else:
-        addr_to_forge = "someone@example.org"
-
-    print("message to inject:")
-    msg = mailgen.get_encrypted(from_addr=addr_to_forge, to_addr=user3.addr)
-    for line in msg.split("\n")[:4]:
-        print(f"   {line}")
-
-    lp.sec("Send forged mail and check remote postfix lmtp processing result")
-    remote_log = remote.iter_output("journalctl -t postfix/lmtp")
-    user1.smtp.sendmail(from_addr=user1.addr, to_addrs=[user3.addr], msg=msg)
-    for line in remote_log:
-        # print(line)
-        if "500 invalid from" in line and user3.addr in line:
-            break
-    else:
-        pytest.fail("remote postfix/filtermail failed to reject message")
-
-    # check that the logged in user (who sent the forged msg) got a non-delivery notice
-    for message in user1.imap.fetch_all_messages():
-        if "Invalid FROM" in message and addr_to_forge in message:
-            return
-    pytest.fail(f"forged From={addr_to_forge} did not cause non-delivery notice")

online-tests/test_0_login.py

@@ -1,4 +1,5 @@
 import pytest
+import smtplib
 
 
 def test_login_basic_functioning(imap_or_smtp, gencreds, lp):
@@ -34,3 +35,178 @@ def test_login_same_password(imap_or_smtp, gencreds):
     imap_or_smtp.login(user1, password1)
     imap_or_smtp.connect()
     imap_or_smtp.login(user2, password1)
+
+
+@pytest.mark.xfail(reason="Only rate limit is internal as well now")
+def test_no_internal_rate_limit(smtp, gencreds):
+    """Test that there is no rate limit between accounts on the same chatmail server."""
+    user, password = gencreds()
+    to_addr, = gencreds()
+    smtp.connect()
+    smtp.login(user, password)
+
+    mail = "\r\n".join(
+        [
+            "Subject: ...",
+            f"From: <{user}>",
+            f"To: <{to_addr}>",
+            "Date: Sun, 15 Oct 2023 16:43:21 +0000",
+            "Message-ID: <Mr.UVyJWZmkCKM.hGzNc6glBE_@c2.testrun.org>",
+            "In-Reply-To: <Mr.MvmCz-GQbi_.6FGRkhDf05c@c2.testrun.org>",
+            "References: <Mr.3gckbNy5bch.uK3Hd2Ws6-w@c2.testrun.org>",
+            "\t<Mr.MvmCz-GQbi_.6FGRkhDf05c@c2.testrun.org>",
+            "Chat-Version: 1.0",
+            f"Autocrypt: addr={user}; prefer-encrypt=mutual;",
+            "\tkeydata=xjMEZSwWjhYJKwYBBAHaRw8BAQdAQBEhqeJh0GueHB6kF/DUQqYCxARNBVokg/AzT+7LqH",
+            "\trNFzxiYXJiYXpAYzIudGVzdHJ1bi5vcmc+wosEEBYIADMCGQEFAmUsFo4CGwMECwkIBwYVCAkKCwID",
+            "\tFgIBFiEEFTfUNvVnY3b9F7yHnmme1PfUhX8ACgkQnmme1PfUhX9A4AEAnHWHp49eBCMHK5t66gYPiW",
+            "\tXQuB1mwUjzGfYWB+0RXUoA/0xcQ3FbUNlGKW7Blp6eMFfViv6Mv2d3kNSXACB6nmcMzjgEZSwWjhIK",
+            "\tKwYBBAGXVQEFAQEHQBpY5L2M1XHo0uxf8SX1wNLBp/OVvidoWHQF2Jz+kJsUAwEIB8J4BBgWCAAgBQ",
+            "\tJlLBaOAhsMFiEEFTfUNvVnY3b9F7yHnmme1PfUhX8ACgkQnmme1PfUhX/INgEA37AJaNvruYsJVanP",
+            "\tIXnYw4CKd55UAwl8Zcy+M2diAbkA/0fHHcGV4r78hpbbL1Os52DPOdqYQRauIeJUeG+G6bQO",
+            "MIME-Version: 1.0",
+            'Content-Type: multipart/encrypted; protocol="application/pgp-encrypted";',
+            '\tboundary="YFrteb74qSXmggbOxZL9dRnhymywAi"',
+            "",
+            "",
+            "--YFrteb74qSXmggbOxZL9dRnhymywAi",
+            "Content-Description: PGP/MIME version identification",
+            "Content-Type: application/pgp-encrypted",
+            "",
+            "Version: 1",
+            "",
+            "",
+            "--YFrteb74qSXmggbOxZL9dRnhymywAi",
+            "Content-Description: OpenPGP encrypted message",
+            'Content-Disposition: inline; filename="encrypted.asc";',
+            'Content-Type: application/octet-stream; name="encrypted.asc"',
+            "",
+            "-----BEGIN PGP MESSAGE-----",
+            "",
+            "wU4DhW3gBZ/VvCYSAQdA8bMs2spwbKdGjVsL1ByPkNrqD7frpB73maeL6I6SzDYg",
+            "O5G53tv339RdKq3WRcCtEEvxjHlUx2XNwXzC04BpmfvBTgNfPUyLDzjXnxIBB0Ae",
+            "8ymwGvXMCCimHXN0Dg8Ui62KOi03h0UgheoHWovJSCDF4CKre/xtFr3nL7lq/PKI",
+            "JsjVNz7/RK9FSXF6WwfONtLCyQGEuVAsB/KXfCBEyfKhaMwGHvhujRidGW5uV1no",
+            "lMGl3ODmo29Lgeu2uSE7EpJRZoe6hU6ddmBkqxax61ZtkaFlGFFpdo2K8balNNdz",
+            "ZsJ/9mmI9x3oOJ4/l1nhQbUO9ADbs7gJhFdV5Qkp30b5fCI7bU+aoe1ccBbLe/WM",
+            "YUty1PqcuQT7XjA+XmYuL261tvW8pBetT+i33/E2d8PzzYt2IuK9qeevyS+yxdwA",
+            "kfwejFWzzsUlJaDxs1x4XOxkMgSj+jo+g12dFOb7fyClsAnq23iDb8AuaT/BScAI",
+            "+lO+gher69+6LmM7VGHLG5k762J1jTaQCaKt1s8TAWV99Eo4491vL6fyvk3l/Cfg",
+            "RXSwiWFgj19Pn0Rq7CD9v22UE2vdUMBTcV4aw79mClk1YQ23jbF0y5DCjPdJ62Zo",
+            "tskBgFt3NoWV80jZ76zIBLrrjLwCCll8JjJtFwSkt2GX5RFBsVa4A8IDht9RtEk7",
+            "rrHgbSZQfkauEi/mH3/6CDZoLqSHudUZ7d4MaJwun1TkFYGe2ORwGJd4OBj3oGJp",
+            "H8YBwCpk///L/fKjX0Gg3M8nrpM4wrRFhPKidAgO/kcm25X4+ZHlVkWBTCt5RWKI",
+            "fHh6oLDZCqCfcgMkE1KKmwfIHaUkhq5BPRigwy6i5dh1DM4+1UCLh3dxzVbqE9b9",
+            "61NB19nXdRtDA2sOUnj9ve6m/wEPyCb6/zBQZqvCBYb1/AjdXpUrFT+DbpfyxaXN",
+            "XfhDVb5mNqNM/IVj0V5fvTc6vOfYbzQtPm10H+FdWWfb+rJRfyC3MA2w2IqstFe3",
+            "w3bu2iE6CQvSqRvge+ZqLKt/NqYwOURiUmpuklbl3kPJ97+mfKWoiqk8Iz1VY+bb",
+            "NMUC7aoGv+jcoj+WS6PYO8N6BeRVUUB3ZJSf8nzjgxm1/BcM+UD3BPrlhT11ODRs",
+            "baifGbprMWwt3dhb8cQgRT8GPdpO1OsDkzL6iikMjLHWWiA99GV6ruiHsIPw6boW",
+            "A6/uSOskbDHOROotKmddGTBd0iiHXAoQsJFt1ZjUkt6EHrgWs+GAvrvKpXs1mrz8",
+            "uj3GwEFrHS+Xuf2UDgpszYT3hI2cL/kUtGakVR7m7vVMZqXBUbZdGAEb1PZNPwsI",
+            "E4aMK02+EVB+tSN4Fzj99N2YD0inVYt+oPjr2tHhUS6aSGBNS/48Ki47DOg4Sxkn",
+            "lkOWnEbCD+XTnbDd",
+            "=agR5",
+            "-----END PGP MESSAGE-----",
+            "",
+            "",
+            "--YFrteb74qSXmggbOxZL9dRnhymywAi--",
+            "",
+            "",
+        ]
+    ).encode()
+    for i in range(100):
+        print("Sending mail", str(i))
+        smtp.conn.sendmail(user, to_addr, mail)
+
+
+def test_exceed_rate_limit(smtp, gencreds):
+    """Test that the outbound rate limit is exceeded if we send a lot of messages at once."""
+    user, password = gencreds()
+    smtp.connect()
+    smtp.login(user, password)
+
+    to_addr = "foobar@example.org"
+    mail = "\r\n".join(
+        [
+            "Subject: ...",
+            f"From: <{user}>",
+            f"To: <{to_addr}>",
+            "Date: Sun, 15 Oct 2023 16:43:21 +0000",
+            "Message-ID: <Mr.UVyJWZmkCKM.hGzNc6glBE_@c2.testrun.org>",
+            "In-Reply-To: <Mr.MvmCz-GQbi_.6FGRkhDf05c@c2.testrun.org>",
+            "References: <Mr.3gckbNy5bch.uK3Hd2Ws6-w@c2.testrun.org>",
+            "\t<Mr.MvmCz-GQbi_.6FGRkhDf05c@c2.testrun.org>",
+            "Chat-Version: 1.0",
+            f"Autocrypt: addr={user}; prefer-encrypt=mutual;",
+            "\tkeydata=xjMEZSwWjhYJKwYBBAHaRw8BAQdAQBEhqeJh0GueHB6kF/DUQqYCxARNBVokg/AzT+7LqH",
+            "\trNFzxiYXJiYXpAYzIudGVzdHJ1bi5vcmc+wosEEBYIADMCGQEFAmUsFo4CGwMECwkIBwYVCAkKCwID",
+            "\tFgIBFiEEFTfUNvVnY3b9F7yHnmme1PfUhX8ACgkQnmme1PfUhX9A4AEAnHWHp49eBCMHK5t66gYPiW",
+            "\tXQuB1mwUjzGfYWB+0RXUoA/0xcQ3FbUNlGKW7Blp6eMFfViv6Mv2d3kNSXACB6nmcMzjgEZSwWjhIK",
+            "\tKwYBBAGXVQEFAQEHQBpY5L2M1XHo0uxf8SX1wNLBp/OVvidoWHQF2Jz+kJsUAwEIB8J4BBgWCAAgBQ",
+            "\tJlLBaOAhsMFiEEFTfUNvVnY3b9F7yHnmme1PfUhX8ACgkQnmme1PfUhX/INgEA37AJaNvruYsJVanP",
+            "\tIXnYw4CKd55UAwl8Zcy+M2diAbkA/0fHHcGV4r78hpbbL1Os52DPOdqYQRauIeJUeG+G6bQO",
+            "MIME-Version: 1.0",
+            'Content-Type: multipart/encrypted; protocol="application/pgp-encrypted";',
+            '\tboundary="YFrteb74qSXmggbOxZL9dRnhymywAi"',
+            "",
+            "",
+            "--YFrteb74qSXmggbOxZL9dRnhymywAi",
+            "Content-Description: PGP/MIME version identification",
+            "Content-Type: application/pgp-encrypted",
+            "",
+            "Version: 1",
+            "",
+            "",
+            "--YFrteb74qSXmggbOxZL9dRnhymywAi",
+            "Content-Description: OpenPGP encrypted message",
+            'Content-Disposition: inline; filename="encrypted.asc";',
+            'Content-Type: application/octet-stream; name="encrypted.asc"',
+            "",
+            "-----BEGIN PGP MESSAGE-----",
+            "",
+            "wU4DhW3gBZ/VvCYSAQdA8bMs2spwbKdGjVsL1ByPkNrqD7frpB73maeL6I6SzDYg",
+            "O5G53tv339RdKq3WRcCtEEvxjHlUx2XNwXzC04BpmfvBTgNfPUyLDzjXnxIBB0Ae",
+            "8ymwGvXMCCimHXN0Dg8Ui62KOi03h0UgheoHWovJSCDF4CKre/xtFr3nL7lq/PKI",
+            "JsjVNz7/RK9FSXF6WwfONtLCyQGEuVAsB/KXfCBEyfKhaMwGHvhujRidGW5uV1no",
+            "lMGl3ODmo29Lgeu2uSE7EpJRZoe6hU6ddmBkqxax61ZtkaFlGFFpdo2K8balNNdz",
+            "ZsJ/9mmI9x3oOJ4/l1nhQbUO9ADbs7gJhFdV5Qkp30b5fCI7bU+aoe1ccBbLe/WM",
+            "YUty1PqcuQT7XjA+XmYuL261tvW8pBetT+i33/E2d8PzzYt2IuK9qeevyS+yxdwA",
+            "kfwejFWzzsUlJaDxs1x4XOxkMgSj+jo+g12dFOb7fyClsAnq23iDb8AuaT/BScAI",
+            "+lO+gher69+6LmM7VGHLG5k762J1jTaQCaKt1s8TAWV99Eo4491vL6fyvk3l/Cfg",
+            "RXSwiWFgj19Pn0Rq7CD9v22UE2vdUMBTcV4aw79mClk1YQ23jbF0y5DCjPdJ62Zo",
+            "tskBgFt3NoWV80jZ76zIBLrrjLwCCll8JjJtFwSkt2GX5RFBsVa4A8IDht9RtEk7",
+            "rrHgbSZQfkauEi/mH3/6CDZoLqSHudUZ7d4MaJwun1TkFYGe2ORwGJd4OBj3oGJp",
+            "H8YBwCpk///L/fKjX0Gg3M8nrpM4wrRFhPKidAgO/kcm25X4+ZHlVkWBTCt5RWKI",
+            "fHh6oLDZCqCfcgMkE1KKmwfIHaUkhq5BPRigwy6i5dh1DM4+1UCLh3dxzVbqE9b9",
+            "61NB19nXdRtDA2sOUnj9ve6m/wEPyCb6/zBQZqvCBYb1/AjdXpUrFT+DbpfyxaXN",
+            "XfhDVb5mNqNM/IVj0V5fvTc6vOfYbzQtPm10H+FdWWfb+rJRfyC3MA2w2IqstFe3",
+            "w3bu2iE6CQvSqRvge+ZqLKt/NqYwOURiUmpuklbl3kPJ97+mfKWoiqk8Iz1VY+bb",
+            "NMUC7aoGv+jcoj+WS6PYO8N6BeRVUUB3ZJSf8nzjgxm1/BcM+UD3BPrlhT11ODRs",
+            "baifGbprMWwt3dhb8cQgRT8GPdpO1OsDkzL6iikMjLHWWiA99GV6ruiHsIPw6boW",
+            "A6/uSOskbDHOROotKmddGTBd0iiHXAoQsJFt1ZjUkt6EHrgWs+GAvrvKpXs1mrz8",
+            "uj3GwEFrHS+Xuf2UDgpszYT3hI2cL/kUtGakVR7m7vVMZqXBUbZdGAEb1PZNPwsI",
+            "E4aMK02+EVB+tSN4Fzj99N2YD0inVYt+oPjr2tHhUS6aSGBNS/48Ki47DOg4Sxkn",
+            "lkOWnEbCD+XTnbDd",
+            "=agR5",
+            "-----END PGP MESSAGE-----",
+            "",
+            "",
+            "--YFrteb74qSXmggbOxZL9dRnhymywAi--",
+            "",
+            "",
+        ]
+    ).encode()
+    for i in range(100):
+        print("Sending mail", str(i))
+        try:
+            smtp.conn.sendmail(user, to_addr, mail)
+        except smtplib.SMTPSenderRefused as e:
+            if i == 0:
+                pytest.fail(f"rate limit was exceeded too early with msg {i} - maybe wait a minute before testing?")
+            if i < 41:
+                pytest.fail(f"rate limit was exceeded too early with msg {i}")
+            assert e.smtp_code == 450
+            assert b'4.7.1 Error: too much mail from' in e.smtp_error
+            return
+    pytest.fail("Rate limit was not exceeded")