diff --git a/src/github_sdk.py b/src/github_sdk.py
index cf28d01..f0dfc07 100644
--- a/src/github_sdk.py
+++ b/src/github_sdk.py
@@ -6,11 +6,16 @@
 import logging
 import uuid
 from datetime import datetime
+from urllib.parse import urlparse
 
 import requests
 from sentry_sdk.envelope import Envelope
 from sentry_sdk.utils import format_timestamp
 
+logger = logging.getLogger(__name__)
+
+SENTRY_HOST_SUFFIX = ".sentry.io"
+
 
 class GithubSentryError(Exception):
     pass
@@ -33,11 +38,14 @@ class GithubClient:
     def __init__(self, token, dsn, dry_run=False) -> None:
         self.token = token
         self.dry_run = dry_run
+        self.sentry_key = None
+        self.sentry_project_url = None
         if dsn:
-            base_uri, project_id = dsn.rsplit("/", 1)
-            self.sentry_key = base_uri.rsplit("@")[0].rsplit("https://")[1]
-            # '{BASE_URI}/api/{PROJECT_ID}/{ENDPOINT}/'
-            self.sentry_project_url = f"{base_uri}/api/{project_id}/envelope/"
+            self.sentry_key, self.sentry_project_url = _parse_sentry_dsn(dsn)
+            if not self.sentry_project_url:
+                logger.warning(
+                    "Skipping trace ingestion because configured DSN host is invalid.",
+                )
 
     def _fetch_github(self, url):
         headers = {"Authorization": f"token {self.token}"}
@@ -108,6 +116,9 @@ def _generate_trace(self, job):
         return transaction
 
     def _send_envelope(self, trace):
+        if not self.sentry_project_url or not self.sentry_key:
+            logger.warning("Skipping envelope upload because DSN is not valid.")
+            return
         if self.dry_run:
             return
         envelope = Envelope()
@@ -148,6 +159,25 @@ def send_trace(self, job):
             return self._send_envelope(trace)
 
 
+def _parse_sentry_dsn(dsn):
+    parsed = urlparse(dsn)
+    project_id = parsed.path.strip("/")
+
+    if (
+        parsed.scheme != "https"
+        or not parsed.hostname
+        or not parsed.hostname.endswith(SENTRY_HOST_SUFFIX)
+        or not parsed.username
+        or not project_id
+    ):
+        return None, None
+
+    # '{BASE_URI}/api/{PROJECT_ID}/{ENDPOINT}/'
+    base_uri = f"{parsed.scheme}://{parsed.netloc}"
+    sentry_project_url = f"{base_uri}/api/{project_id}/envelope/"
+    return parsed.username, sentry_project_url
+
+
 def _base_transaction(job):
     return {
         "event_id": get_uuid(),
diff --git a/tests/test_github_sdk.py b/tests/test_github_sdk.py
index 7f7e401..da640cf 100644
--- a/tests/test_github_sdk.py
+++ b/tests/test_github_sdk.py
@@ -12,6 +12,7 @@
 from sentry_sdk.utils import format_timestamp
 
 from src.github_sdk import GithubClient
+from src.github_sdk import _parse_sentry_dsn
 
 DSN = "https://foo@random.ingest.sentry.io/bar"
 TOKEN = "irrelevant"
@@ -44,6 +45,18 @@ def test_initialize_without_setting_token():
     assert msg == f"{prepend}__init__() missing 1 required positional argument: 'token'"
 
 
+def test_reject_invalid_sentry_host():
+    client = GithubClient(dsn="https://foo@sentryalert.ru/bar", token=TOKEN)
+    assert client.sentry_key is None
+    assert client.sentry_project_url is None
+
+
+def test_parse_sentry_dsn_accepts_sentry_io_hosts():
+    key, project_url = _parse_sentry_dsn("https://foo@o123.ingest.sentry.io/456")
+    assert key == "foo"
+    assert project_url == "https://foo@o123.ingest.sentry.io/api/456/envelope/"
+
+
 @responses.activate
 def test_ensure_raise_error_on_github_api_failure():
     """We want to delegate to the app using the SDK to handle the error."""
@@ -153,6 +166,23 @@ def test_send_trace(
     for k, v in resp.request.headers.items():
         assert envelope_headers[k] == v
 
+
+@responses.activate
+def test_send_trace_does_not_post_when_dsn_is_invalid(jobA_job, jobA_runs, jobA_workflow):
+    responses.get(
+        "https://api.github.com/repos/getsentry/sentry/actions/runs/2104746951",
+        json=jobA_runs,
+    )
+    responses.get(
+        "https://api.github.com/repos/getsentry/sentry/actions/workflows/1174556",
+        json=jobA_workflow,
+    )
+
+    client = GithubClient(dsn="https://foo@sentryalert.ru/bar", token=TOKEN)
+    resp = client.send_trace(jobA_job)
+    assert resp is None
+    assert all(call.request.method != "POST" for call in responses.calls)
+
     # XXX: We will deal with this another time
     # assert (
     #     resp.request.body