diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5384918..a9a8b71 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 - **FIX** `Test-DaneRecords` now correctly checks DANE records for domains without MX records.
 - **FIX** The DMARC `fo` token is now parsed correctly when multiple values are present.
 - **FIX** The DMARC `rf` token is now parsed correctly.
+- **FIX** The MTA-STS policy file test returns a better error message when the file does not have the correct CRLF line endings.
 - **FIX** The SPF `exists` and `mx` token parsers no longer generate a spurious error when *not* counting DNS lookups.
 - **FIX** IntelliSense's handling of `Test-SpfRecord` has been improved by hiding some internal-use-only parameters.
 - **FIX** Cleaned up `Test-DaneRecords`' output.
diff --git a/MailPolicyExplainer.psd1 b/MailPolicyExplainer.psd1
index 2f89da0..2be47d5 100644
--- a/MailPolicyExplainer.psd1
+++ b/MailPolicyExplainer.psd1
@@ -174,6 +174,7 @@ Many bugs were fixed, too:
 - The DMARC `fo` token is now parsed correctly when multiple values are present.
 - The DMARC `rf` token is now parsed correctly.
 - The IntelliSense handling of `Test-SpfRecord` has been improved by hiding some internal-use-only parameters.
+- The MTA-STS policy file test returns a better error message when the file does not have the correct CRLF line endings.
 - The SPF `exists` and `mx` token parsers no longer generate a spurious error when not counting DNS lookups.
 - Cleaned up the output of `Test-DaneRecords` a little.
 - Miscellaneous code cleanup.
diff --git a/src/MailPolicyExplainer.psm1 b/src/MailPolicyExplainer.psm1
index 213f1c1..92f6596 100644
--- a/src/MailPolicyExplainer.psm1
+++ b/src/MailPolicyExplainer.psm1
@@ -867,7 +867,21 @@ Function Test-MtaStsPolicy
 		Write-BadNews "MTA-STS Policy: It was found, but was returned with the wrong content type ($($policy.Headers.'Content-Type'))."
 	}
 	Else {
-		$policy.Content.Split("`r`n") | ForEach-Object {
+		#region Make sure the file has the correct line endings.
+		# The MTA-STS RFC says that they should end with CRLF (i.e., "`r`n").
+		# Split it up two different ways and see if we get the same results.
+		# If not, then someone probably saved the file with UNIX ("`r") endings.
+		# We're going to be strict and refuse to parse the file in this case.
+		$lines   = $policy.Content.Split("`r`n")
+		$LFlines = $policy.Content -Split "`r?`n"
+		
+		If ($lines -ne $LFLines) {
+			Write-BadNews "MTA-STS Policy: The policy file does not have the correct CRLF line endings!"
+			Return
+		}
+		#endregion
+		
+		$lines | ForEach-Object {
 			$line = $_.Trim()
 			If ($line -CLike 'version: *') {
 				If (($line -Split ':')[1].Trim() -Eq 'STSv1') {
@@ -1279,7 +1293,7 @@ Function Test-SpfRecord
 			If ($CountDnsLookups) {
 				$DnsLookups.Value++
 			}
-			
+
 			If ($token -Match "^\+?exists:.*") {
 				Write-GoodNews "${RecordType}: Accept mail if $($token -Replace '\+' -Replace 'exists:') resolves to an A record.$(Write-DnsLookups $DnsLookups -Enabled:$CountDnsLookups)"
 			}