Remove smtp_tls_security_level exception for nauta.cu

nauta.cu MX servers don't support STARTTLS
and we have maintained this exception to allow delivery to nauta.cu.
Since nauta.cu has blocked largest chatmail relay instances,
we can remove this exception.
Even if it works today for some chatmail servers,
they will likely be blocked once the number of users grows.
Even now users from nauta.cu cannot practically participate
in groups.

.github/ISSUE_TEMPLATE/config.yml

@@ -1,5 +1 @@
 blank_issues_enabled: true
-contact_links:
-  - name: Mutual Help Chat Group
-    url: https://i.delta.chat/#6CBFF8FFD505C0FDEA20A66674F2916EA8FBEE99&a=invitebot%40nine.testrun.org&g=Chatmail%20Mutual%20Help&x=7sFF7Ik50pWv6J1z7RVC5527&i=X69wTFfvCfs3d-JzqP0kVA3i&s=ibp-447dU-wUq-52QanwAtWc
-    about: If you have troubles setting up the relay server, feel free to ask here.

CHANGELOG.md

@@ -2,6 +2,15 @@
 
 ## untagged
 
+- acmetool: use ECDSA keys instead of RSA
+  ([#689](https://github.com/chatmail/relay/pull/689))
+
+- Require TLS 1.2 for outgoing SMTP connections
+  ([#685](https://github.com/chatmail/relay/pull/685))
+
+- require STARTTLS for incoming port 25 connections
+  ([#684](https://github.com/chatmail/relay/pull/684))
+
 - filtermail: run CPU-intensive handle_DATA in a thread pool executor
   ([#676](https://github.com/chatmail/relay/pull/676))
 
@@ -21,7 +30,7 @@
   ([#650](https://github.com/chatmail/relay/pull/650))
 
 - filtermail: accept mails from Protonmail
-  ([#616](https://github.com/chatmail/relay/pull/655))
+  ([#616](https://github.com/chatmail/relay/pull/616))
 
 - Ignore all RCPT TO: parameters
   ([#651](https://github.com/chatmail/relay/pull/651))
@@ -54,7 +63,7 @@
   to only do a single iteration over sometimes millions of messages
   instead of doing "find" commands that iterate 9 times over the messages. 
   Provide an "fsreport" CLI for more fine grained analysis of message files. 
-  ([#637](https://github.com/chatmail/relay/pull/632))
+  ([#637](https://github.com/chatmail/relay/pull/637))
 
 
 ## 1.7.0 2025-09-11

README.md

@@ -180,6 +180,10 @@ The components of chatmail are:
 - [Iroh relay](https://www.iroh.computer/docs/concepts/relay) 
   which helps client devices to establish Peer-to-Peer connections 
 
+- [TURN](https://github.com/chatmail/chatmail-turn)
+  to enable relay users to start webRTC calls
+  even if a p2p connection can't be established
+
 - and the chatmaild services, explained in the next section:
 
 ### chatmaild
@@ -304,6 +308,8 @@ Chatmail address creation will be denied while this file is present.
 [Nginx](https://www.nginx.com/) listens on port 8443 (HTTPS-ALT) and 443 (HTTPS).
 Port 443 multiplexes HTTPS, IMAP and SMTP using ALPN to redirect connections to ports 8443, 465 or 993.
 [acmetool](https://hlandau.github.io/acmetool/) listens on port 80 (HTTP).
+[chatmail-turn](https://github.com/chatmail/chatmail-turn) listens on UDP port 3478 (STUN/TURN),
+and temporarily opens UDP ports when users request them. UDP port range is not restricted, any free port may be allocated.
 
 chatmail-core based apps will, however, discover all ports and configurations
 automatically by reading the [autoconfig XML file](https://www.ietf.org/archive/id/draft-bucksch-autoconfig-00.html) from the chatmail relay server.

chatmaild/src/chatmaild/expire.py

@@ -22,11 +22,30 @@ def iter_mailboxes(basedir, maxnum):
         print_info(f"no mailboxes found at: {basedir}")
         return
 
-    for name in os.listdir(basedir)[:maxnum]:
+    for name in os_listdir_if_exists(basedir)[:maxnum]:
         if "@" in name:
             yield MailboxStat(basedir + "/" + name)
 
 
+def get_file_entry(path):
+    """return a FileEntry or None if the path does not exist or is not a regular file."""
+    try:
+        st = os.stat(path)
+    except FileNotFoundError:
+        return None
+    if not S_ISREG(st.st_mode):
+        return None
+    return FileEntry(path, st.st_mtime, st.st_size)
+
+
+def os_listdir_if_exists(path):
+    """return a list of names obtained from os.listdir or an empty list if the path does not exist."""
+    try:
+        return os.listdir(path)
+    except FileNotFoundError:
+        return []
+
+
 class MailboxStat:
     last_login = None
 
@@ -40,19 +59,23 @@ class MailboxStat:
 
         # scan all relevant files (without recursion)
         old_cwd = os.getcwd()
-        os.chdir(self.basedir)
+        try:
-        for name in os.listdir("."):
+            os.chdir(self.basedir)
+        except FileNotFoundError:
+            return
+        for name in os_listdir_if_exists("."):
             if name in ("cur", "new", "tmp"):
-                for msg_name in os.listdir(name):
+                for msg_name in os_listdir_if_exists(name):
-                    relpath = name + "/" + msg_name
+                    entry = get_file_entry(f"{name}/{msg_name}")
-                    st = os.stat(relpath)
+                    if entry is not None:
-                    self.messages.append(FileEntry(relpath, st.st_mtime, st.st_size))
+                        self.messages.append(entry)
+
             else:
-                st = os.stat(name)
+                entry = get_file_entry(name)
-                if S_ISREG(st.st_mode):
+                if entry is not None:
-                    self.extrafiles.append(FileEntry(name, st.st_mtime, st.st_size))
+                    self.extrafiles.append(entry)
                     if name == "password":
-                        self.last_login = st.st_mtime
+                        self.last_login = entry.mtime
         self.extrafiles.sort(key=lambda x: -x.size)
         os.chdir(old_cwd)
 
@@ -80,9 +103,13 @@ class Expiry:
             shutil.rmtree(mboxdir)
         self.del_mboxes += 1
 
-    def remove_file(self, path):
+    def remove_file(self, path, mtime=None):
         if self.verbose:
-            print_info(f"removing {path}")
+            if mtime is not None:
+                date = datetime.fromtimestamp(mtime).strftime("%b %d")
+                print_info(f"removing {date} {path}")
+            else:
+                print_info(f"removing {path}")
         if not self.dry:
             try:
                 os.unlink(path)
@@ -104,18 +131,27 @@ class Expiry:
             return
 
         # all to-be-removed files are relative to the mailbox basedir
-        os.chdir(mbox.basedir)
+        try:
+            os.chdir(mbox.basedir)
+        except FileNotFoundError:
+            print_info(f"mailbox not found/vanished {mbox.basedir}")
+            return
+
         mboxname = os.path.basename(mbox.basedir)
         if self.verbose:
-            print_info(f"checking for mailbox messages in: {mboxname}")
+            date = datetime.fromtimestamp(mbox.last_login) if mbox.last_login else None
+            if date:
+                print_info(f"checking mailbox {date.strftime('%b %d')} {mboxname}")
+            else:
+                print_info(f"checking mailbox (no last_login) {mboxname}")
         self.all_files += len(mbox.messages)
         for message in mbox.messages:
             if message.mtime < cutoff_mails:
-                self.remove_file(message.relpath)
+                self.remove_file(message.relpath, mtime=message.mtime)
             elif message.size > 200000 and message.mtime < cutoff_large_mails:
                 # we only remove noticed large files (not unnoticed ones in new/)
                 if message.relpath.startswith("cur/"):
-                    self.remove_file(message.relpath)
+                    self.remove_file(message.relpath, mtime=message.mtime)
             else:
                 continue
             changed = True

chatmaild/src/chatmaild/tests/test_expire.py

@@ -6,7 +6,13 @@ from pathlib import Path
 
 import pytest
 
-from chatmaild.expire import FileEntry, MailboxStat, iter_mailboxes
+from chatmaild.expire import (
+    FileEntry,
+    MailboxStat,
+    get_file_entry,
+    iter_mailboxes,
+    os_listdir_if_exists,
+)
 from chatmaild.expire import main as expiry_main
 from chatmaild.fsreport import main as report_main
 
@@ -127,3 +133,18 @@ def test_expiry_cli_old_files(capsys, example_config, mbox1):
                 pytest.fail(f"failed to remove {path}\n{err}")
 
     assert "shouldstay" not in err
+
+
+def test_get_file_entry(tmp_path):
+    assert get_file_entry(str(tmp_path.joinpath("123123"))) is None
+    p = tmp_path.joinpath("x")
+    p.write_text("hello")
+    entry = get_file_entry(str(p))
+    assert entry.size == 5
+    assert entry.mtime
+
+
+def test_os_listdir_if_exists(tmp_path):
+    tmp_path.joinpath("x").write_text("hello")
+    assert len(os_listdir_if_exists(str(tmp_path))) == 1
+    assert len(os_listdir_if_exists(str(tmp_path.joinpath("123123")))) == 0

cmdeploy/src/cmdeploy/__init__.py

@@ -338,9 +338,9 @@ def _install_dovecot_package(package: str, arch: str):
 
     match (package, arch):
         case ("core", "amd64"):
-            sha256 = "43f593332e22ac7701c62d58b575d2ca409e0f64857a2803be886c22860f5587"
+            sha256 = "dd060706f52a306fa863d874717210b9fe10536c824afe1790eec247ded5b27d"
         case ("core", "arm64"):
-            sha256 = "4d21eba1a83f51c100f08f2e49f0c9f8f52f721ebc34f75018e043306da993a7"
+            sha256 = "e7548e8a82929722e973629ecc40fcfa886894cef3db88f23535149e7f730dc9"
         case ("imapd", "amd64"):
             sha256 = "8d8dc6fc00bbb6cdb25d345844f41ce2f1c53f764b79a838eb2a03103eebfa86"
         case ("imapd", "arm64"):

cmdeploy/src/cmdeploy/acmetool/target.yaml.j2

@@ -1,7 +1,8 @@
 request:
   provider: https://acme-v02.api.letsencrypt.org/directory
   key:
-    type: rsa
+    type: ecdsa
+    ecdsa-curve: nistp256
   challenge:
     webroot-paths:
     - /var/www/html/.well-known/acme-challenge

cmdeploy/src/cmdeploy/dovecot/dovecot.conf.j2

@@ -70,6 +70,12 @@ userdb {
 # Mailboxes are stored in the "mail" directory of the vmail user home.
 mail_location = maildir:{{ config.mailboxes_dir }}/%u
 
+# index/cache files are not very useful for chatmail relay operations 
+# but it's not clear how to disable them completely. 
+# According to https://doc.dovecot.org/2.3/settings/advanced/#core_setting-mail_cache_max_size
+# if the cache file becomes larger than the specified size, it is truncated by dovecot 
+mail_cache_max_size = 500K
+
 namespace inbox {
   inbox = yes
 

cmdeploy/src/cmdeploy/postfix/main.cf.j2

@@ -25,7 +25,7 @@ smtp_tls_security_level=verify
 # <https://www.postfix.org/postconf.5.html#smtp_tls_servername>
 smtp_tls_servername = hostname
 smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
-smtp_tls_policy_maps = inline:{nauta.cu=may}
+smtp_tls_protocols = >=TLSv1.2
 smtpd_tls_protocols = >=TLSv1.2
 
 # Disable anonymous cipher suites

cmdeploy/src/cmdeploy/postfix/master.cf.j2

@@ -14,6 +14,7 @@ smtp      inet  n       -       y       -       -       smtpd -v
 {%- else %}
 smtp      inet  n       -       y       -       -       smtpd 
 {%- endif %}
+  -o smtpd_tls_security_level=encrypt
   -o smtpd_proxy_filter=127.0.0.1:{{ config.filtermail_smtp_port_incoming }}
 submission inet n       -       y       -       5000    smtpd
   -o syslog_name=postfix/submission

cmdeploy/src/cmdeploy/tests/online/test_0_login.py

@@ -1,5 +1,5 @@
 import queue
-import socket
+import smtplib
 import threading
 
 import pytest
@@ -91,25 +91,23 @@ def test_concurrent_logins_same_account(
 
 def test_no_vrfy(chatmail_config):
     domain = chatmail_config.mail_domain
-    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+
-    sock.settimeout(10)
+    s = smtplib.SMTP(domain)
-    try:
+    s.starttls()
-        sock.connect((domain, 25))
+
-    except socket.timeout:
+    s.putcmd("vrfy", f"wrongaddress@{chatmail_config.mail_domain}")
-        pytest.skip(f"port 25 not reachable for {domain}")
+    result = s.getreply()
-    banner = sock.recv(1024)
-    print(banner)
-    sock.send(b"VRFY wrongaddress@%s\r\n" % (chatmail_config.mail_domain.encode(),))
-    result = sock.recv(1024)
     print(result)
-    sock.send(b"VRFY echo@%s\r\n" % (chatmail_config.mail_domain.encode(),))
+    s.putcmd("vrfy", f"echo@{chatmail_config.mail_domain}")
-    result2 = sock.recv(1024)
+    result2 = s.getreply()
     print(result2)
-    assert result[0:10] == result2[0:10]
+    assert result[0] == result2[0] == 252
-    sock.send(b"VRFY wrongaddress\r\n")
+    assert result[1][0:6] == result2[1][0:6] == b"2.0.0 "
-    result = sock.recv(1024)
+    s.putcmd("vrfy", "wrongaddress")
+    result = s.getreply()
     print(result)
-    sock.send(b"VRFY echo\r\n")
+    s.putcmd("vrfy", "echo")
-    result2 = sock.recv(1024)
+    result2 = s.getreply()
     print(result2)
-    assert result[0:10] == result2[0:10] == b"252 2.0.0 "
+    assert result[0] == result2[0] == 252
+    assert result[1][0:6] == result2[1][0:6] == b"2.0.0 "

cmdeploy/src/cmdeploy/tests/online/test_1_basic.py

@@ -143,6 +143,7 @@ def test_reject_missing_dkim(cmsetup, maildata, from_addr):
         "encrypted.eml", from_addr=from_addr, to_addr=recipient.addr
     ).as_string()
     conn = smtplib.SMTP(cmsetup.maildomain, 25, timeout=10)
+    conn.starttls()
 
     with conn as s:
         with pytest.raises(smtplib.SMTPDataError, match="No valid DKIM signature"):