Fix DMARC fo parser to allow multiple values.

The DMARC parser for the forensic reporting options tag (`fo`) did
not support multiple values, in violation of the specification.
This commit fixes the parser so that tokens such as "fo=0:1:s:d"
are correctly recognized as valid.

CHANGELOG.md

@@ -1,6 +1,7 @@
 # MailPolicyExplainer Change Log
 
 ## Version 1.3.1 (Wednesday, December 9, 2023)
+- **FIX** The DMARC `fo` token is now parsed correctly when multiple values are present.
 - **FIX** The DMARC `rf` token is now parsed correctly.
 
 ## Version 1.3.0 (Tuesday, November 7, 2023)

MailPolicyExplainer.psd1

@@ -167,7 +167,9 @@ PrivateData = @{
 		IconUri = 'https://raw.githubusercontent.com/rhymeswithmogul/MailPolicyExplainer/main/icon/PSGallery.png'
 
 		# ReleaseNotes of this module
-		ReleaseNotes = '- The DMARC "rf" token is now parsed correctly.'
+		ReleaseNotes = 'This release fixes many bugs:
+- The DMARC `fo` token is now parsed correctly when multiple values are present.
+- The DMARC `rf` token is now parsed correctly.'
 
 	} # End of PSData hashtable
 

src/MailPolicyExplainer.psm1

@@ -526,7 +526,7 @@ Function Test-DmarcRecord
 		}
 		ElseIf ($token -Like 'fo=*') {
 			If ($DmarcRecord -Match 'ruf=') {
-				Switch ($token -Replace 'fo=') {
+				Switch ($token.Substring(3) -Split ':') {
 					0    { Write-Informational 'DMARC: Generate a forensic report if SPF and DKIM both fail (default).' }
 					1    { Write-Informational 'DMARC: Generate a forensic report if either SPF or DKIM fail.'}
 					'd'  { Write-Informational 'DMARC: Generate a forensic report if DKIM fails, even if DMARC passes.' }