diff --git a/build.sh b/build.sh
index 724a4b5..efb3c21 100755
--- a/build.sh
+++ b/build.sh
@@ -58,9 +58,21 @@ read -p "SMTP Port (default: 465 for SSL, 587 for STARTTLS): " SMTP_PORT
 SMTP_PORT=${SMTP_PORT:-465}
 
 read -p "SMTP Username (default: same as IMAP): " SMTP_USER
-SMTP_USER=${SMTP_USER:-$IMAP_USER}
+read -sp SMTP_USER
+if [ -z "$SMTP_USER" ] && [ -z "$SMTP_PASS" ]; then
+  # Only use IMAP defaults if BOTH SMTP username and password are empty
+  SMTP_USER=${SMTP_USER:-$IMAP_USER}
+else
+  SMTP_USER=${SMTP_USER}
+fi
 
 read -sp "SMTP Password (default: same as IMAP): " SMTP_PASS
+if [ -z "$SMTP_USER" ] && [ -z "$SMTP_PASS" ]; then
+  # Only use IMAP defaults if BOTH SMTP username and password are empty
+  SMTP_PASS=${SMTP_PASS:-$IMAP_PASS}
+else
+  SMTP_PASS=${SMTP_PASS}
+fi
 if [ -z "$SMTP_PASS" ]; then
   SMTP_PASS="$IMAP_PASS"
 fi