The setter/getter wasn't as dumb as I originally assumed.

(copied from the mailer plugin)

core/src/main/java/jenkins/model/JenkinsLocationConfiguration.java

@@ -50,10 +50,17 @@ public class JenkinsLocationConfiguration extends GlobalConfiguration {
     }
 
     public String getAdminAddress() {
-        return adminAddress;
+        String v = adminAddress;
+        if(v==null)     v = Messages.Mailer_Address_Not_Configured();
+        return v;
     }
 
     public void setAdminAddress(String adminAddress) {
+        if(adminAddress.startsWith("\"") && adminAddress.endsWith("\"")) {
+            // some users apparently quote the whole thing. Don't konw why
+            // anyone does this, but it's a machine's job to forgive human mistake
+            adminAddress = adminAddress.substring(1,adminAddress.length()-1);
+        }
         this.adminAddress = adminAddress;
         save();
     }

core/src/main/resources/jenkins/model/Messages.properties

@@ -60,7 +60,9 @@ CLI.shutdown.shortDescription=Immediately shuts down Jenkins server
 CLI.safe-shutdown.shortDescription=Puts Jenkins into the quiet mode, wait for existing builds to be completed, and then shut down Jenkins.
 
 DefaultProjectNamingStrategy.DisplayName=Default
-PatternProjectNamingStrategy.DisplayName=Pattern
 
+Mailer.Address.Not.Configured=address not configured yet <nobody@nowhere>
+
+PatternProjectNamingStrategy.DisplayName=Pattern
 PatternProjectNamingStrategy.NamePatternRequired=Name Pattern is required
 PatternProjectNamingStrategy.NamePatternInvalidSyntax=regular expression's syntax is invalid.
\ No newline at end of file

core/src/main/resources/jenkins/model/Messages_da.properties

@@ -49,3 +49,5 @@ CLI.restart.shortDescription=Genstart Jenkins
 CLI.cancel-quiet-down.shortDescription=Sl\u00e5 effekten af "quite-down" kommandoen fra.
 CLI.reload-configuration.shortDescription=Genindl\u00e6s alle data fra filsystemet. \
 Nyttigt hvis du har modificeret konfigurationsfiler direkte, udenom Jenkins.
+
+Mailer.Address.Not.Configured=Adresse ikke konfigureret <nobody@nowhere>

core/src/main/resources/jenkins/model/Messages_de.properties

@@ -52,3 +52,4 @@ CLI.cancel-quiet-down.shortDescription=Wirkung des Befehls "quiet-down" wieder a
 CLI.reload-configuration.shortDescription=Alle Daten im Speicher verwerfen und Konfiguration neu von Festplatte laden. Dies ist n\u00fctzlich, wenn Sie \u00c4nderungen direkt im Dateisystem vorgenommen haben.
 CLI.safe-restart.shortDescription=Startet Jenkins neu.
 
+Mailer.Address.Not.Configured=Adresse nicht konfiguriert <nobody@nowhere>

core/src/main/resources/jenkins/model/Messages_es.properties

@@ -59,3 +59,5 @@ Hudson.JobNameConventionNotApplyed=el nombre ''{0}'' no cumple el patr
 CLI.shutdown.shortDescription=Apagar inmediatamente Jenkins.
 CauseOfInterruption.ShortDescription=Cancelado por {0}
 PatternProjectNamingStrategy.NamePatternInvalidSyntax=La sintaxis de la expresin regular no es vlida
+
+Mailer.Address.Not.Configured=Direccin no configurada todava <nobody@nowhere>

core/src/main/resources/jenkins/model/Messages_ja.properties

@@ -58,4 +58,6 @@ DefaultProjectNamingStrategy.DisplayName=\u30c7\u30d5\u30a9\u30eb\u30c8
 PatternProjectNamingStrategy.DisplayName=\u30d1\u30bf\u30fc\u30f3
 
 PatternProjectNamingStrategy.NamePatternRequired=\u30d1\u30bf\u30fc\u30f3\u306f\u5fc5\u9808\u3067\u3059\u3002
-PatternProjectNamingStrategy.NamePatternInvalidSyntax=\u6b63\u898f\u8868\u73fe\u306b\u8aa4\u308a\u304c\u3042\u308a\u307e\u3059\u3002
\ No newline at end of file
+PatternProjectNamingStrategy.NamePatternInvalidSyntax=\u6b63\u898f\u8868\u73fe\u306b\u8aa4\u308a\u304c\u3042\u308a\u307e\u3059\u3002
+
+Mailer.Address.Not.Configured=\u307e\u3060\u30a2\u30c9\u30ec\u30b9\u304c\u8a2d\u5b9a\u3055\u308c\u3066\u3044\u307e\u305b\u3093\u3002 <nobody@nowhere>

core/src/main/resources/jenkins/model/Messages_pt_BR.properties

@@ -39,7 +39,10 @@ Hudson.NodeDescription=NO mestre do Jenkins
 CLI.safe-restart.shortDescription=Seguro reiniciar o Jenkins
 CLI.quiet-down.shortDescription=Desativar em modo silencioso, em prepara\u00e7\u00e3o para o rein\u00edcio. N\u00e3o come\u00e7e nenhuma constru\u00e7\u00e3o.
 CLI.cancel-quiet-down.shortDescription=Cancela o comando "quiet-down"
-CLI.reload-configuration.shortDescription=Descarta todo o conteudo de mem\u00f3ria e recarrega novamente a partir do arquivo. /
+CLI.reload-configuration.shortDescription=Descarta todo o conteudo de mem\u00f3ria e recarrega novamente a partir do arquivo. \
 Indicado quando voc\u00ea modificou os arquivos diretamente no disco.
 CLI.restart.shortDescription=Reiniciar o Jenkins
 CLI.keep-build.shortDescription=Marcar a constru\u00e7\u00e3o como permanente
+
+# address not configured yet <nobody@nowhere>
+Mailer.Address.Not.Configured=Endere\u00e7o ainda n\u00e3o configurado <nobody@nowhere>