diff --git a/src/content/daily-email/2023-09-18.md b/src/content/daily-email/2023-09-18.md
new file mode 100644
index 00000000..979c7f4e
--- /dev/null
+++ b/src/content/daily-email/2023-09-18.md
@@ -0,0 +1,27 @@
+---
+title: >
+  Increasing test coverage with regression tests
+pubDate: 2023-09-18
+permalink: >
+  archive/2023/09/18/increasing-test-coverage-with-regression-tests
+tags:
+  - software-development
+  - automated-testing
+  - test-driven-development
+---
+
+Automated test suites don't tell you everything works - they tell you what you've tested isn't broken.
+
+Having tests doesn't mean your code is bug-free. There could be edge cases or scenarios you haven't tested for that contain bugs, even though your test suite is passing.
+
+## What do we do?
+
+When you find a bug, try replicating it within an automated test before attempting to fix it.
+
+Once you have a failing test and can replicate the issue, go ahead and fix it.
+
+If the test passes, you know you've fixed the bug and solved the issue.
+
+## Here's the thing
+
+Now you have this test, you cannot re-add the bug again without the test failing. You've prevented anyone from accidentally re-introducing it in the future and increased your test coverage.