diff --git a/README.md b/README.md
index 3791de6..7d11006 100644
--- a/README.md
+++ b/README.md
@@ -13,16 +13,16 @@ send to the core — inheriting rotation, proxy, retry, and result for free.
 ## Install
 
 ```
-aiowebhooks @ git+ssh://git@git.rethinkstudios.io/rethink-public/aiowebhooks.git@v0.1.4
+aiowebhooks @ git+ssh://git@git.rethinkstudios.io/rethink-public/aiowebhooks.git@v0.1.5
 # discord embeds / identity helpers need the extra:
-aiowebhooks[discord] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aiowebhooks.git@v0.1.4
+aiowebhooks[discord] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aiowebhooks.git@v0.1.5
 ```
 
 The base pulls `aiohttp` and `commons` (for the retry/backoff engine). Only
 `aiowebhooks[discord]` adds `discord.py` (>=2.3, mainline — not discord.py-self), and
 only for `DiscordWebhook`.
 
-Drop the `@v0.1.4` suffix from the line above to install the latest unpinned.
+Drop the `@v0.1.5` suffix from the line above to install the latest unpinned.
 
 ## Core sender
 
@@ -75,8 +75,14 @@ Status retries run through `commons.aretry` (exponential backoff + cap):
 - **429** — always retried, capped by `max_retries`. When a wait is parseable (body
   `retry_after` first — Discord sends seconds — then the `Retry-After` header) it sleeps
   that value before retrying; a 429 with no parseable wait (edge/Cloudflare/generic
-  webhook) still retries under aretry's backoff rather than failing one-shot.
+  webhook) still retries under aretry's backoff rather than failing one-shot. A
+  non-finite value (`inf`/`nan`) is rejected outright and a finite value is clamped to
+  `MAX_RETRY_AFTER` (300s) — a server-controlled wait can never stall a `send()` past
+  that ceiling, however large or malformed the value it sends.
 - **5xx** — retried with exponential backoff, capped by `max_retries`.
+- **connection/timeout errors** — retried with exponential backoff, capped by
+  `max_retries`, same as a 5xx (with no proxy provider; see below for the
+  proxy-rotation path).
 - **4xx** (other than 429) — fails immediately (no retry), returned as `ok=False`.
 
 Exceeding a cap returns a failed result rather than looping — and the result carries the
@@ -104,7 +110,8 @@ On a timeout/connection error the current proxy is burned and the next is tried,
 `max_proxy_retries`. Hitting the cap, or **any exception from the provider's
 `get()`/`burn()`** (the provider is duck-typed and never imported, so its exception
 types can't be caught by class), returns a failed result — never an infinite loop, never
-an escape. With no provider, a timeout just fails after normal retry.
+an escape. With no provider, a timeout/connection error is retried directly under
+`max_retries` (the same cap and backoff a 5xx gets) instead of burn+rotate.
 
 ## Discord (`aiowebhooks[discord]`)
 
@@ -141,6 +148,21 @@ Without the extra installed, importing `aiowebhooks` still works; constructing o
 
 ## Changelog
 
+### v0.1.5
+
+- **429 `retry_after` bounded:** a non-finite server-controlled wait (`inf`/`nan`, from
+  the body `retry_after` or the `Retry-After` header) is now rejected outright, and a
+  finite wait is clamped to `MAX_RETRY_AFTER` (300s). Previously a bare `float()` parse
+  slept the value verbatim, unbounded and outside `max_retries` accounting — an
+  adversarial or ms-vs-s-misconfigured server could stall a `send()` for hours.
+- **Connection/timeout errors now retry without a proxy provider:** previously
+  `aiohttp.ClientError`/`asyncio.TimeoutError` with no `proxies=` set failed one-shot,
+  contradicting both the README and the single most retry-worthy failure class. Now it
+  retries under `commons.aretry`'s backoff, capped by `max_retries`, same as a 5xx —
+  and still returns `ok=False` (never raises) once retries are exhausted. Proxy-rotation
+  behavior (burn + rotate, capped by `max_proxy_retries`) is unchanged when a provider
+  is set.
+
 ### v0.1.4
 
 - **Never-raises net widened:** an unexpected exception that escapes a send attempt (a
diff --git a/pyproject.toml b/pyproject.toml
index df689e9..c5df956 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "aiowebhooks"
-version = "0.1.4"
+version = "0.1.5"
 description = "async webhook sender (aiohttp) with round-robin urls, retry, and proxy rotation; optional discord.py embeds"
 requires-python = ">=3.10"
 dependencies = [
diff --git a/src/aiowebhooks/sender.py b/src/aiowebhooks/sender.py
index 3fbc7a6..724c23b 100644
--- a/src/aiowebhooks/sender.py
+++ b/src/aiowebhooks/sender.py
@@ -1,13 +1,20 @@
 """core async webhook sender (aiohttp only, no discord knowledge).
 
 `Webhook` posts a JSON dict to a url (or round-robins a pool), handling 429/5xx
-retries and optional proxy rotation, and always returns a `WebhookResult` — it
-never raises on a send failure. the discord layer builds payloads and delegates
-the actual POST here so it inherits rotation / proxy / retry / result.
+retries, connection/timeout retries, and optional proxy rotation, and always
+returns a `WebhookResult` — it never raises on a send failure. the discord layer
+builds payloads and delegates the actual POST here so it inherits rotation / proxy
+/ retry / result.
+
+a 429's server-controlled `retry_after` wait is bounded: non-finite values
+(inf/nan) are rejected and finite values are clamped to `MAX_RETRY_AFTER`, so an
+adversarial or misconfigured server can never stall a send() past a bounded
+ceiling.
 """
 
 import asyncio
 import logging
+import math
 from typing import Dict, List, Optional, Union
 from urllib.parse import unquote, urlsplit
 
@@ -19,6 +26,17 @@ from .result import WebhookResult
 
 log = logging.getLogger(__name__)
 
+MAX_RETRY_AFTER = 300.0
+"""ceiling (seconds) honored from a server-controlled 429 retry_after/Retry-After
+
+a server can send an arbitrarily large or non-finite wait (float('inf'), a
+Cloudflare-scale value, or a ms-vs-s unit mismatch turning 5s into 5000s); sleeping
+that verbatim would stall a send() far past its ClientTimeout and outside
+max_retries accounting, breaking the 'always returns a WebhookResult' contract.
+non-finite values are rejected outright (treated as unparseable); finite values are
+clamped to this ceiling.
+"""
+
 
 class _Retryable(Exception):
     """internal signal: a retryable HTTP status (429/5xx); carries the response
@@ -90,18 +108,27 @@ class Webhook:
 
     @staticmethod
     def _retry_after(status: int, headers, body) -> Optional[float]:
-        """seconds to wait on a 429, from body retry_after then Retry-After header"""
+        """seconds to wait on a 429, from body retry_after then Retry-After header
+
+        non-finite values (inf/nan) are rejected as unparseable; finite values are
+        clamped to MAX_RETRY_AFTER so a server-controlled wait can never stall a
+        send() past a bounded ceiling.
+        """
         if status != 429:
             return None
         if isinstance(body, dict) and body.get("retry_after") is not None:
             try:
-                return float(body["retry_after"])
+                value = float(body["retry_after"])
+                if math.isfinite(value):
+                    return max(0.0, min(value, MAX_RETRY_AFTER))
             except (TypeError, ValueError):
                 pass
         header = headers.get("Retry-After") if headers else None
         if header is not None:
             try:
-                return float(header)
+                value = float(header)
+                if math.isfinite(value):
+                    return max(0.0, min(value, MAX_RETRY_AFTER))
             except (TypeError, ValueError):
                 pass
         return None
@@ -110,9 +137,10 @@ class Webhook:
         """post a json payload to the next pool url; always returns a result
 
         handles 429 (wait + retry, capped by max_retries), 5xx (retry, capped), and
-        timeout/connection errors with optional proxy rotation (burn + next, capped
-        by max_proxy_retries). 4xx other than 429 fail immediately. never raises on a
-        send failure.
+        timeout/connection errors: with a proxy provider, burn + rotate to the next
+        proxy (capped by max_proxy_retries) before failing; without one, retried
+        directly under max_retries like a 5xx. 4xx other than 429 fail immediately.
+        never raises on a send failure.
         """
         url = self._next_url()
         session = self._session
@@ -130,11 +158,13 @@ class Webhook:
     ) -> WebhookResult:
         """status-retry (via commons.aretry) wrapping proxy rotation; never raises
 
-        commons.aretry owns the 429/5xx backoff schedule + retry cap (max_retries),
-        retrying on the internal _Retryable signal. on exhaustion it re-raises the
-        last _Retryable, whose carried result is the REAL last response (not a
-        synthetic status-0). proxy rotation on connection errors lives inside the
-        attempt and is capped separately.
+        commons.aretry owns the 429/5xx/no-provider-connection-error backoff schedule
+        + retry cap (max_retries), retrying on the internal _Retryable signal. on
+        exhaustion it re-raises the last _Retryable, whose carried result is the REAL
+        last response (not a synthetic status-0). proxy rotation on connection errors
+        lives inside the attempt and is capped separately (max_proxy_retries); once a
+        provider's rotation cap is hit that failure is terminal, not retried again
+        via aretry.
         """
         counter = [0]
         try:
@@ -163,8 +193,12 @@ class Webhook:
 
         raises _Retryable (carrying the real response) on a 429/5xx so the caller's
         aretry applies backoff; honors an explicit 429 retry_after by sleeping it
-        before signalling. returns a final WebhookResult on success or a terminal
-        (non-retryable) failure — never lets a provider/connection error escape.
+        before signalling. a connection/timeout error also raises _Retryable when no
+        proxy provider is set, so it retries under aretry's backoff + max_retries
+        instead of failing one-shot; with a provider, the same error first drives
+        burn+rotate up to max_proxy_retries, and only becomes terminal (not retried
+        via aretry) once that cap is hit. returns a final WebhookResult on success or
+        a terminal (non-retryable) failure — never lets a provider error escape.
 
         `counter` is a per-call mutable cell ([0]) owned by the calling `_send_loop`,
         so the attempt count is local to one `send()` and concurrent sends on the
@@ -217,7 +251,10 @@ class Webhook:
                         # generic webhook) still retries under aretry's backoff + cap.
                         # note: aretry ALSO sleeps its backoff between retries, so an
                         # honored retry_after is additive (retry_after + backoff) — this
-                        # only ever over-waits, never under-waits the server's hint
+                        # only ever over-waits, never under-waits the server's hint.
+                        # non-finite values (inf/nan) are rejected and finite values are
+                        # clamped to MAX_RETRY_AFTER by _retry_after, so a server-controlled
+                        # wait can never stall this attempt past a bounded ceiling
                         wait = self._retry_after(status, resp.headers, body)
                         if wait is not None:
                             log.warning("webhook 429 on %s; honoring retry_after %.3fs", url, wait)
@@ -230,18 +267,30 @@ class Webhook:
                     return result
 
             except (aiohttp.ClientError, asyncio.TimeoutError) as error:
-                if self._proxies is not None and proxy_tries < self.max_proxy_retries:
-                    if self._burn(last_proxy):
-                        proxy_tries += 1
-                        continue
+                if self._proxies is not None:
+                    if proxy_tries < self.max_proxy_retries:
+                        if self._burn(last_proxy):
+                            proxy_tries += 1
+                            continue
+                        return WebhookResult(
+                            ok=False, status=None, url=url, attempts=attempts,
+                            error="proxies exhausted", proxy=last_proxy,
+                        )
                     return WebhookResult(
                         ok=False, status=None, url=url, attempts=attempts,
-                        error="proxies exhausted", proxy=last_proxy,
+                        error=f"{type(error).__name__}: {error}", proxy=last_proxy,
                     )
-                return WebhookResult(
+                # no proxy provider: a connection/timeout error is the single most
+                # retry-worthy failure class (the 5xx equivalent already retries under
+                # aretry) — raise _Retryable so aretry applies backoff + max_retries
+                # instead of failing one-shot. aretry re-raises this same _Retryable on
+                # exhaustion, and _send_loop's `except _Retryable` returns its carried
+                # result, so the never-raises / always-returns-a-WebhookResult contract
+                # still holds after retries run out.
+                raise _Retryable(WebhookResult(
                     ok=False, status=None, url=url, attempts=attempts,
                     error=f"{type(error).__name__}: {error}", proxy=last_proxy,
-                )
+                ))
 
     def _burn(self, proxy: Optional[str]) -> bool:
         """burn the current proxy; return False if it can't be rotated