fix(email): resolve IMAP/SMTP host from config and validate before connecting

The email adapter read address/host purely from env vars and never stripped
them, so a missing or whitespace-padded EMAIL_IMAP_HOST reached
imaplib.IMAP4_SSL("") and surfaced as the misleading
"[Errno 8] nodename nor servname provided, or not known" — sending users down a
DNS rabbit hole when the real problem was an empty/dirty host string. A
config.yaml-only setup also left the host empty because __init__ ignored
PlatformConfig.extra, even though the "connected" check, the send helper, and
`hermes config show` already read address/imap_host/smtp_host from it.

Resolve address/imap_host/smtp_host from the env var first, then fall back to
config.extra, and strip surrounding whitespace — matching the send helper's
existing pattern. Validate the required settings at the start of connect() and
return False with an actionable message instead of attempting a connection with
an empty host.

Adds regression tests for whitespace stripping, config.extra fallback, and the
no-IMAP-attempt-on-missing-host path.

plugins/platforms/email/adapter.py

@@ -307,11 +307,20 @@ class EmailAdapter(BasePlatformAdapter):
     def __init__(self, config: PlatformConfig):
         super().__init__(config, Platform.EMAIL)
 
-        self._address = os.getenv("EMAIL_ADDRESS", "")
+        # Resolve connection settings from the env vars first, then fall back to
+        # PlatformConfig.extra (address/imap_host/smtp_host) — the canonical dict
+        # gateway.config populates and that the "connected" check, the
+        # send-helper, and `hermes config show` already read. Without the
+        # fallback a config.yaml-only setup left these empty. Host/address values
+        # are stripped: a stray space or newline made IMAP4_SSL raise the
+        # misleading ``[Errno 8] nodename nor servname`` (an unresolvable name)
+        # instead of an obvious "host not set" error.
+        extra = config.extra or {}
+        self._address = (os.getenv("EMAIL_ADDRESS", "") or extra.get("address", "")).strip()
         self._password = os.getenv("EMAIL_PASSWORD", "")
-        self._imap_host = os.getenv("EMAIL_IMAP_HOST", "")
+        self._imap_host = (os.getenv("EMAIL_IMAP_HOST", "") or extra.get("imap_host", "")).strip()
         self._imap_port = env_int("EMAIL_IMAP_PORT", 993)
-        self._smtp_host = os.getenv("EMAIL_SMTP_HOST", "")
+        self._smtp_host = (os.getenv("EMAIL_SMTP_HOST", "") or extra.get("smtp_host", "")).strip()
         self._smtp_port = env_int("EMAIL_SMTP_PORT", 587)
         self._poll_interval = env_int("EMAIL_POLL_INTERVAL", 15)
 
@@ -319,7 +328,6 @@ class EmailAdapter(BasePlatformAdapter):
         #   platforms:
         #     email:
         #       skip_attachments: true
-        extra = config.extra or {}
         self._skip_attachments = extra.get("skip_attachments", False)
 
         # Track message IDs we've already processed to avoid duplicates
@@ -396,6 +404,27 @@ class EmailAdapter(BasePlatformAdapter):
 
     async def connect(self) -> bool:
         """Connect to the IMAP server and start polling for new messages."""
+        # Validate up front so a missing host surfaces as an actionable config
+        # error instead of IMAP4_SSL("") raising the cryptic
+        # ``[Errno 8] nodename nor servname provided, or not known``.
+        missing = [
+            name
+            for name, value in (
+                ("EMAIL_ADDRESS", self._address),
+                ("EMAIL_PASSWORD", self._password),
+                ("EMAIL_IMAP_HOST", self._imap_host),
+                ("EMAIL_SMTP_HOST", self._smtp_host),
+            )
+            if not value
+        ]
+        if missing:
+            logger.error(
+                "[Email] Not configured — missing %s. Set it via `hermes gateway "
+                "setup` (env) or platforms.email in config.yaml.",
+                ", ".join(missing),
+            )
+            return False
+
         try:
             # Test IMAP connection
             imap = imaplib.IMAP4_SSL(self._imap_host, self._imap_port, timeout=30)

tests/gateway/test_email.py

@@ -1392,5 +1392,68 @@ class TestConnectSmtp(unittest.TestCase):
         self.assertIs(_socket.getaddrinfo, original_getaddrinfo)
 
 
+class TestConnectionConfigResolution(unittest.TestCase):
+    """Host/address resolution and pre-connect validation (#49736)."""
+
+    def test_host_and_address_whitespace_stripped(self):
+        """A stray space/newline must not reach IMAP4_SSL as part of the host.
+
+        Whitespace in the host produced the misleading
+        ``[Errno 8] nodename nor servname`` (unresolvable name) instead of a
+        successful connection.
+        """
+        from gateway.config import PlatformConfig
+        from plugins.platforms.email.adapter import EmailAdapter
+        with patch.dict(os.environ, {
+            "EMAIL_ADDRESS": "  hermes@test.com\n",
+            "EMAIL_PASSWORD": "secret",
+            "EMAIL_IMAP_HOST": " imap.test.com ",
+            "EMAIL_SMTP_HOST": "smtp.test.com\n",
+        }, clear=False):
+            adapter = EmailAdapter(PlatformConfig(enabled=True))
+        self.assertEqual(adapter._imap_host, "imap.test.com")
+        self.assertEqual(adapter._smtp_host, "smtp.test.com")
+        self.assertEqual(adapter._address, "hermes@test.com")
+
+    def test_falls_back_to_platform_config_extra(self):
+        """When env vars are absent, settings come from PlatformConfig.extra —
+        the same dict gateway.config populates and `hermes config show` reads."""
+        from gateway.config import PlatformConfig
+        from plugins.platforms.email.adapter import EmailAdapter
+        cfg = PlatformConfig(enabled=True)
+        cfg.extra.update({
+            "address": "hermes@test.com",
+            "imap_host": "imap.test.com",
+            "smtp_host": "smtp.test.com",
+        })
+        with patch.dict(os.environ, {
+            "EMAIL_ADDRESS": "", "EMAIL_IMAP_HOST": "", "EMAIL_SMTP_HOST": "",
+            "EMAIL_PASSWORD": "secret",
+        }, clear=False):
+            adapter = EmailAdapter(cfg)
+        self.assertEqual(adapter._imap_host, "imap.test.com")
+        self.assertEqual(adapter._smtp_host, "smtp.test.com")
+        self.assertEqual(adapter._address, "hermes@test.com")
+
+    def test_connect_aborts_without_attempting_imap_when_host_missing(self):
+        """A missing host returns False without the cryptic DNS error."""
+        import asyncio
+        from gateway.config import PlatformConfig
+        from plugins.platforms.email.adapter import EmailAdapter
+        with patch.dict(os.environ, {
+            "EMAIL_ADDRESS": "hermes@test.com",
+            "EMAIL_PASSWORD": "secret",
+            "EMAIL_IMAP_HOST": "",
+            "EMAIL_SMTP_HOST": "smtp.test.com",
+        }, clear=False):
+            adapter = EmailAdapter(PlatformConfig(enabled=True))
+
+        with patch("imaplib.IMAP4_SSL") as mock_imap:
+            result = asyncio.run(adapter.connect())
+
+        self.assertFalse(result)
+        mock_imap.assert_not_called()
+
+
 if __name__ == "__main__":
     unittest.main()