diff --git a/postinstall b/postinstall
index 3f65394..6a3b3c5 100755
--- a/postinstall
+++ b/postinstall
@@ -418,29 +418,40 @@ ask_mail_config(){
     smtpauth=0
     senderaddress=""
     displayname=""
+    if [ -f /etc/postfix/sender_canonical_maps ]; then
+        senderaddress=$(grep "@" -m1 /etc/postfix/sender_canonical_maps | cut -d '<' -f2 | cut -d '>' -f1)
+        displayname=$(grep "@" -m1 /etc/postfix/sender_canonical_maps | cut -d' ' -f5)
+    fi
     recipientaddress=""
     smtphost=$(grep relayhost /etc/postfix/main.cf | cut -d : -f1 | cut -d ' ' -f3 | cut -d ']' -f1 | cut -d '[' -f2)
     smtpport=25
     username=""
+    password=""
+    if [ -f /etc/postfix/sasl_passwd ]; then
+        username=$(cat /etc/postfix/sasl_passwd | cut -d ' ' -f2- | cut -d':' -f1)
+        password=$(cat /etc/postfix/sasl_passwd | cut -d ' ' -f2- | cut -d':' -f2-)
+    else
+        username=$senderaddress
+    fi
     if whiptail --title "MAIL DELIVERY" \
     --backtitle "$PROG" \
     --yes-button "MAIL CONFIG" \
     --no-button "SKIP" \
     --yesno "Do you want to configure postfix with a smarthost?" 9 76 ; then
         mailconfig=1
-        if ! senderaddress=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter your sender email address." 9 76 3>&1 1>&2 2>&3); then cancel_dialog; fi
         if ! displayname=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter your sender display name." 9 76 $(hostname -f) 3>&1 1>&2 2>&3); then cancel_dialog; fi
         if ! recipientaddress=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter the email address to receive notifications." 9 76 $(pvesh get access/users/root@pam --output-format yaml| grep email | cut -d' ' -f2) 3>&1 1>&2 2>&3); then cancel_dialog; fi
         if ! smtphost=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter the servername of your smarthost." 9 76 $smtphost 3>&1 1>&2 2>&3); then cancel_dialog; fi
         smtpport=$(inputbox_int 'MAIL DELIVERY' 'Please enter the port of your smarthost' 7 $(grep relayhost /etc/postfix/main.cf | cut -d':' -f2))
+        if ! senderaddress=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter your sender email address." 9 76 3>&1 1>&2 2>&3); then cancel_dialog; fi
         if whiptail --title "MAIL DELIVERY" \
         --backtitle "$PROG" \
         --yes-button "CONFIGURE AUTH" \
         --no-button "SKIP" \
         --yesno "Do you want to configure authentication against your smarthost?" 9 76 ; then
             smtpauth=1
-            if ! username=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter the username for authentication." 9 76 3>&1 1>&2 2>&3); then cancel_dialog; fi
-            if ! password=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --passwordbox "Please enter the passsword for authentication." 9 76 3>&1 1>&2 2>&3); then cancel_dialog; fi
+            if ! username=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter the username for authentication." 9 76 $username 3>&1 1>&2 2>&3); then cancel_dialog; fi
+            if ! password=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --passwordbox "Please enter the passsword for authentication." 9 76 $password 3>&1 1>&2 2>&3); then cancel_dialog; fi
         fi
     fi
 }