Fix spurious error message in SPF exists parser.

Like the `mx` parser, the `exists` token parser in `Test-SpfRecord`
also suffered from the same bug when *not* running in recursive
mode.  This has been corrected.

CHANGELOG.md

@@ -5,7 +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 SPF `mx` token parser no longer generates a spurious error when not counting DNS lookups.
+- **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.
 - **FIX** Miscellaneous code cleanup to improve future maintenance.

MailPolicyExplainer.psd1

@@ -174,7 +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 SPF `mx` token parser no longer generates a spurious error when not counting DNS lookups.
+- 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.
 '

src/MailPolicyExplainer.psm1

@@ -1276,7 +1276,10 @@ Function Test-SpfRecord
 		#region Check exists tokens
 		ElseIf ($token -Match "^[\+\-\?\~]?exists:.*")
 		{
-			$DnsLookups.Value++
+			If ($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)"
 			}