diff --git a/notify/mail.sh b/notify/mail.sh
index dbecc3a5..ec9aa0de 100644
--- a/notify/mail.sh
+++ b/notify/mail.sh
@@ -5,6 +5,7 @@
 #MAIL_BIN="sendmail"
 #MAIL_FROM="yyyy@gmail.com"
 #MAIL_TO="yyyy@gmail.com"
+#MAIL_NOVALIDATE=""
 
 mail_send() {
   _subject="$1"
@@ -14,22 +15,28 @@ mail_send() {
   _debug "_content" "$_content"
   _debug "_statusCode" "$_statusCode"
 
+  MAIL_NOVALIDATE="${MAIL_NOVALIDATE:-$(_readaccountconf_mutable MAIL_NOVALIDATE)}"
+  if [ -n "$MAIL_NOVALIDATE" ]; then
+    _saveaccountconf_mutable MAIL_NOVALIDATE 1
+  else
+    _clearaccountconf "MAIL_NOVALIDATE"
+  fi
+
   MAIL_BIN="${MAIL_BIN:-$(_readaccountconf_mutable MAIL_BIN)}"
   if [ -n "$MAIL_BIN" ] && ! _exists "$MAIL_BIN"; then
     _err "It seems that the command $MAIL_BIN is not in path."
     return 1
   fi
-  _MAIL_CMD=$(_mail_cmnd)
+  _MAIL_BIN=$(_mail_bin)
   if [ -n "$MAIL_BIN" ]; then
     _saveaccountconf_mutable MAIL_BIN "$MAIL_BIN"
   else
     _clearaccountconf "MAIL_BIN"
   fi
-  _MAIL_BODY=$(_mail_body)
 
   MAIL_FROM="${MAIL_FROM:-$(_readaccountconf_mutable MAIL_FROM)}"
   if [ -n "$MAIL_FROM" ]; then
-    if ! _contains "$MAIL_FROM" "@"; then
+    if ! _mail_valid "$MAIL_FROM"; then
       _err "It seems that the MAIL_FROM=$MAIL_FROM is not a valid email address."
       return 1
     fi
@@ -39,7 +46,7 @@ mail_send() {
 
   MAIL_TO="${MAIL_TO:-$(_readaccountconf_mutable MAIL_TO)}"
   if [ -n "$MAIL_TO" ]; then
-    if ! _contains "$MAIL_TO" "@"; then
+    if ! _mail_valid "$MAIL_TO"; then
       _err "It seems that the MAIL_TO=$MAIL_TO is not a valid email address."
       return 1
     fi
@@ -55,8 +62,9 @@ mail_send() {
 
   contenttype="text/plain; charset=utf-8"
   subject="=?UTF-8?B?$(echo "$_subject" | _base64)?="
-  result=$({ echo "$_MAIL_BODY" | eval "$_MAIL_CMD"; } 2>&1)
+  result=$({ _mail_body | eval "$(_mail_cmnd)"; } 2>&1)
 
+  # shellcheck disable=SC2181
   if [ $? -ne 0 ]; then
     _debug "mail send error."
     _err "$result"
@@ -67,7 +75,7 @@ mail_send() {
   return 0
 }
 
-_mail_cmnd() {
+_mail_bin() {
   if [ -n "$MAIL_BIN" ]; then
     _MAIL_BIN="$MAIL_BIN"
   elif _exists "sendmail"; then
@@ -83,6 +91,10 @@ _mail_cmnd() {
     return 1
   fi
 
+  echo "$_MAIL_BIN"
+}
+
+_mail_cmnd() {
   case $(basename "$_MAIL_BIN") in
     sendmail)
       if [ -n "$MAIL_FROM" ]; then
@@ -105,16 +117,22 @@ _mail_cmnd() {
 }
 
 _mail_body() {
-  if [ "$_MAIL_BIN" = "sendmail" ] || [ "$_MAIL_BIN" = "ssmtp" ]; then
-    if [ -n "$MAIL_FROM" ]; then
-      echo "From: $MAIL_FROM"
-    fi
+  case $(basename "$_MAIL_BIN") in
+    sendmail | ssmtp)
+      if [ -n "$MAIL_FROM" ]; then
+        echo "From: $MAIL_FROM"
+      fi
 
-    echo "To: $MAIL_TO"
-    echo "Subject: $subject"
-    echo "Content-Type: $contenttype"
-    echo
-  fi
+      echo "To: $MAIL_TO"
+      echo "Subject: $subject"
+      echo "Content-Type: $contenttype"
+      echo
+      ;;
+  esac
 
   echo "$_content"
 }
+
+_mail_valid() {
+  [ -n "$MAIL_NOVALIDATE" ] || _contains "$1" "@"
+}