diff --git a/config.inc.php b/config.inc.php
index 5f7278c5..7dd1b132 100644
--- a/config.inc.php
+++ b/config.inc.php
@@ -317,6 +317,7 @@ $CONF['vacation'] = 'NO';
 // This is the autoreply domain that you will need to set in your Postfix
 // transport maps to handle virtual vacations. It does not need to be a
 // real domain (i.e. you don't need to setup DNS for it).
+// This domain must exclusively be used for vacation. Do NOT use it for "normal" mail addresses.
 $CONF['vacation_domain'] = 'autoreply.change-this-to-your.domain.tld';
 
 // Vacation Control
diff --git a/languages/bg.lang b/languages/bg.lang
index 771e6f3b..9ae2037c 100644
--- a/languages/bg.lang
+++ b/languages/bg.lang
@@ -242,6 +242,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Редактиране на домейн';
 $PALANG['pAdminEdit_domain_aliases_text'] = '0 = изключени | -1 = неограничени';
diff --git a/languages/ca.lang b/languages/ca.lang
index 0309f035..e64d479d 100644
--- a/languages/ca.lang
+++ b/languages/ca.lang
@@ -240,6 +240,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Editar un domini';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = ilimitat | 0 = deshabilitar';
diff --git a/languages/cn.lang b/languages/cn.lang
index e9631226..327b5212 100644
--- a/languages/cn.lang
+++ b/languages/cn.lang
@@ -241,6 +241,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = '修改域';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = 禁止 | 0 = 无限制'; # XXX check / compare with pAdminCreate_domain_aliases_text - should be "-1 = disable | ..."
diff --git a/languages/cs.lang b/languages/cs.lang
index 7cbb0b08..4e1d4883 100644
--- a/languages/cs.lang
+++ b/languages/cs.lang
@@ -250,6 +250,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Upravit doménu';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = znepřístupnit | 0 = neomezeně';
diff --git a/languages/da.lang b/languages/da.lang
index 39dda5eb..9d8f0688 100644
--- a/languages/da.lang
+++ b/languages/da.lang
@@ -250,6 +250,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Domæne-aliaset kunne ikke slettes!';
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome']        = 'Redigér et domæne';
 $PALANG['pAdminEdit_domain_aliases_text']   = '-1 = annullér | 0 = uendeligt';
diff --git a/languages/de.lang b/languages/de.lang
index 747dc872..5ff5bcd8 100644
--- a/languages/de.lang
+++ b/languages/de.lang
@@ -247,6 +247,7 @@ $PALANG['mailbox_postdel_failed'] = 'Fehler beim Ausführen des mailbox postdele
 $PALANG['mailbox_postedit_failed'] = 'Fehler beim Ausführen des mailbox postedit-Scripts, überprüfen Sie das Error-Log für Details!';
 $PALANG['mailbox_postcreate_failed'] = 'Fehler beim Ausführen des mailbox postcreate-Scripts, überprüfen Sie das Error-Log für Details!';
 $PALANG['pAdminDelete_alias_domain_error'] = 'Alias-Domain konnte nicht gelöscht werden!';
+$PALANG['domain_conflict_vacation_domain'] = 'Sie können die Vacation-Domain nicht als Maildomain benutzen!';
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Domain bearbeiten';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = ausschalten | 0 = kein Limit';
diff --git a/languages/en.lang b/languages/en.lang
index 06902397..542817da 100644
--- a/languages/en.lang
+++ b/languages/en.lang
@@ -248,6 +248,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!';
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!';
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!';
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!';
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Edit a domain';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = disable | 0 = unlimited';
diff --git a/languages/es.lang b/languages/es.lang
index 7debc670..ccc01038 100644
--- a/languages/es.lang
+++ b/languages/es.lang
@@ -242,6 +242,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = '¡No se pudo eliminar el alias de dominio!'; 
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Editar un dominio';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = deshabilitar | 0 = ilimitado';
diff --git a/languages/et.lang b/languages/et.lang
index 5d8a3f71..5c643fd8 100644
--- a/languages/et.lang
+++ b/languages/et.lang
@@ -241,6 +241,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Redigeeri domeeni';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = keelatud | 0 = piiramatult';
diff --git a/languages/eu.lang b/languages/eu.lang
index c0891327..9c1aee6e 100644
--- a/languages/eu.lang
+++ b/languages/eu.lang
@@ -239,6 +239,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Domeinu bat aldatu';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = desegokitu | 0 = mugagabea';
diff --git a/languages/fi.lang b/languages/fi.lang
index b71c5473..ea8def4e 100644
--- a/languages/fi.lang
+++ b/languages/fi.lang
@@ -241,6 +241,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Domainin aliasta ei voitu poistaa!';
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Muokkaa domainia';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = ei käytössä | 0 = rajoittamaton';
diff --git a/languages/fo.lang b/languages/fo.lang
index 3f29fce1..80c86da7 100644
--- a/languages/fo.lang
+++ b/languages/fo.lang
@@ -241,6 +241,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Broyt navnaøki';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = óvirkja | 0 = óavmarkað';
diff --git a/languages/fr.lang b/languages/fr.lang
index 1dad659b..a7ba035e 100644
--- a/languages/fr.lang
+++ b/languages/fr.lang
@@ -243,6 +243,7 @@ $PALANG['mailbox_postdel_failed'] = 'Le script postdeletion du compte courriel a
 $PALANG['mailbox_postedit_failed'] = 'Le script postedit du compte courriel a échoué, consultez la log!';
 $PALANG['mailbox_postcreate_failed'] = 'Le script postcreate du compte courriel a échoué, consultez la log!';
 $PALANG['pAdminDelete_alias_domain_error'] = 'Impossible de supprimé cet alias de domaine!';
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Modifier un domaine';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = désactivé | 0 = illimité';
diff --git a/languages/hr.lang b/languages/hr.lang
index a6a5dd4c..41c2b3f8 100644
--- a/languages/hr.lang
+++ b/languages/hr.lang
@@ -240,6 +240,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Uredi domenu';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = onemogući | 0 = bezgranično';
diff --git a/languages/hu.lang b/languages/hu.lang
index 919ba3e8..9fb21f99 100644
--- a/languages/hu.lang
+++ b/languages/hu.lang
@@ -247,6 +247,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Domain szerkesztése';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = kikapcsol | 0 = végtelen';
diff --git a/languages/is.lang b/languages/is.lang
index 0b7c16a8..1aa9f087 100644
--- a/languages/is.lang
+++ b/languages/is.lang
@@ -241,6 +241,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Breyta léni';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = óvirkt | 0 = ótakmarkað';
diff --git a/languages/it.lang b/languages/it.lang
index 516a3b60..0b69ad8d 100644
--- a/languages/it.lang
+++ b/languages/it.lang
@@ -242,6 +242,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Modifica un domain';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = disabilita | 0 = illimitati';
diff --git a/languages/ja.lang b/languages/ja.lang
index 3e8171f2..47415a15 100644
--- a/languages/ja.lang
+++ b/languages/ja.lang
@@ -247,6 +247,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'ドメインの修正';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = 無効 | 0 = 無制限';
diff --git a/languages/lt.lang b/languages/lt.lang
index 8c0c05c2..1256381f 100644
--- a/languages/lt.lang
+++ b/languages/lt.lang
@@ -242,6 +242,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Nepavyko panaikinti srities sinonimo!';
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Keisti sritį';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = išjungta(s) | 0 = neribota(s)';
diff --git a/languages/mk.lang b/languages/mk.lang
index ff307d67..5d6c3f64 100644
--- a/languages/mk.lang
+++ b/languages/mk.lang
@@ -242,6 +242,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Измена на домен';
 $PALANG['pAdminEdit_domain_aliases_text'] = '0 = забрането | -1 = неограничено';
diff --git a/languages/nb.lang b/languages/nb.lang
index 4e1c1209..5c306979 100644
--- a/languages/nb.lang
+++ b/languages/nb.lang
@@ -242,6 +242,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Kunne ikke fjerne domenealias!';
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Endre et domene';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = deaktiver | 0 = ubegrenset';
diff --git a/languages/nl.lang b/languages/nl.lang
index 065cdf93..48b57983 100644
--- a/languages/nl.lang
+++ b/languages/nl.lang
@@ -242,6 +242,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Niet in staat domein alias te verwijderen!';
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Bewerk een domein';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = uit | 0 = onbeperkt';
diff --git a/languages/nn.lang b/languages/nn.lang
index ad54db6d..39adbe75 100644
--- a/languages/nn.lang
+++ b/languages/nn.lang
@@ -241,6 +241,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Endre domenet';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = deaktivere | 0 = ubegrenset';
diff --git a/languages/pl.lang b/languages/pl.lang
index 3d732720..798cf439 100644
--- a/languages/pl.lang
+++ b/languages/pl.lang
@@ -244,6 +244,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Nie można usunąć aliasu domeny!';
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Edytuj domenę';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = wyłączone | 0 = bez limitów';
diff --git a/languages/pt-br.lang b/languages/pt-br.lang
index ff226d82..d4815954 100644
--- a/languages/pt-br.lang
+++ b/languages/pt-br.lang
@@ -249,6 +249,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Não foi possível remover o alias de domínio!';
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Edição de domínio.';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = desativar | 0 = ilimitado';
diff --git a/languages/ru.lang b/languages/ru.lang
index 69a2d4d4..99853619 100644
--- a/languages/ru.lang
+++ b/languages/ru.lang
@@ -249,6 +249,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Невозможно удалить домен-алиас!';
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Редактирование домена';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = отключить | 0 = неограниченное';
diff --git a/languages/sk.lang b/languages/sk.lang
index b25d6f1a..98098240 100644
--- a/languages/sk.lang
+++ b/languages/sk.lang
@@ -242,6 +242,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Nepodario sa odstrániť alias domény!';
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Upraviť doménu';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = zakázať | 0 = neobmedzene';
diff --git a/languages/sl.lang b/languages/sl.lang
index 437119da..ba5d02b3 100644
--- a/languages/sl.lang
+++ b/languages/sl.lang
@@ -241,6 +241,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Uredi domeno';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = onemogoči | 0 = neomejeno';
diff --git a/languages/sv.lang b/languages/sv.lang
index 012b77d1..136099f2 100644
--- a/languages/sv.lang
+++ b/languages/sv.lang
@@ -243,6 +243,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Ändra en domän';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = avaktivera | 0 = obegränsat';
diff --git a/languages/tr.lang b/languages/tr.lang
index 1ec9e267..4c1be7c6 100644
--- a/languages/tr.lang
+++ b/languages/tr.lang
@@ -241,6 +241,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = 'Domain düzenle';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = iptal | 0 = limitsiz'; # XXX check - "limisiz" or "limi_t_siz"?
diff --git a/languages/tw.lang b/languages/tw.lang
index 10f7f7ab..00ace3d6 100644
--- a/languages/tw.lang
+++ b/languages/tw.lang
@@ -241,6 +241,7 @@ $PALANG['mailbox_postdel_failed'] = 'The mailbox postdeletion script failed, che
 $PALANG['mailbox_postedit_failed'] = 'The mailbox postedit script failed, check the error log for details!'; # XXX
 $PALANG['mailbox_postcreate_failed'] = 'The mailbox postcreate script failed, check the error log for details!'; # XXX
 $PALANG['pAdminDelete_alias_domain_error'] = 'Unable to remove domain alias!'; # XXX
+$PALANG['domain_conflict_vacation_domain'] = 'You can\'t use the vacation domain as mail domain!'; # XXX
 
 $PALANG['pAdminEdit_domain_welcome'] = '修改網域';
 $PALANG['pAdminEdit_domain_aliases_text'] = '-1 = 禁止 | 0 = 無限制'; # XXX check / compare with pAdminCreate_domain_aliases_text - should be "-1 = disable | ..."
diff --git a/model/DomainHandler.php b/model/DomainHandler.php
index 8db77375..f13dfeb6 100644
--- a/model/DomainHandler.php
+++ b/model/DomainHandler.php
@@ -10,18 +10,23 @@ class DomainHandler extends PFAHandler {
     protected $id_field = 'domain';
     protected $domain_field = 'domain';
 
-   protected function validate_new_id() {
-       $domain_check = check_domain($this->id);
+    protected function validate_new_id() {
+        $domain_check = check_domain($this->id);
 
-       if ($domain_check == '') {
-            return true;
-       } else {
+        if ($domain_check != '') {
             $this->errormsg[$this->id_field] = $domain_check;
             return false;
-       }
-   }
+        }
+
+        if (Config::read('vacation_domain') == $this->id) {
+            $this->errormsg[$this->id_field] = Config::Lang('domain_conflict_vacation_domain');
+            return false;
+        }
+
+        # still here? good.
+        return true;
+    }
 
-    # init $this->struct, $this->db_table and $this->id_field
     protected function initStruct() {
         # TODO: shorter PALANG labels ;-)