diff --git a/CONFIGURATION.md b/CONFIGURATION.md
index dd5b7a7..e716a93 100644
--- a/CONFIGURATION.md
+++ b/CONFIGURATION.md
@@ -56,9 +56,11 @@ SMTP_USERNAME=your-email@gmail.com
 SMTP_PASSWORD=your-app-password
 SMTP_SECURE=true
 MAIL_FROM_ADDRESS=your-email@gmail.com
-MAIL_FROM_NAME=Docmost
+MAIL_FROM_NAME="Docmost"
 ```
 
+**Important**: Values with spaces must be quoted with double quotes.
+
 ### S3 Storage
 
 To use Amazon S3 or compatible storage:
@@ -110,6 +112,34 @@ cloudron exec --app docmost -- env | grep -E "(MAIL|STORAGE|S3)" | sort
 cloudron logs --app docmost
 ```
 
+### .env File Format Errors
+
+If you see errors like `line 1: Docmost: command not found`, your .env file has syntax errors:
+
+1. **Values with spaces must be quoted**:
+   ```bash
+   # Wrong:
+   MAIL_FROM_NAME=My Company
+   
+   # Correct:
+   MAIL_FROM_NAME="My Company"
+   ```
+
+2. **No spaces around equals sign**:
+   ```bash
+   # Wrong:
+   MAIL_DRIVER = smtp
+   
+   # Correct:
+   MAIL_DRIVER=smtp
+   ```
+
+3. **Check for invalid characters**:
+   ```bash
+   # Validate your .env file:
+   cloudron exec --app docmost -- cat /app/data/.env
+   ```
+
 ### Reset to Defaults
 
 To reset to Cloudron defaults, simply remove the custom .env file:
diff --git a/start.sh b/start.sh
index 17f3ed6..2740983 100644
--- a/start.sh
+++ b/start.sh
@@ -102,9 +102,19 @@ fi
 # Load custom environment variables if they exist
 if [ -f "/app/data/.env" ]; then
     echo "=> Loading custom environment variables from /app/data/.env"
-    set -a  # automatically export all variables
-    source /app/data/.env
-    set +a  # stop automatically exporting
+    # Validate .env file format before sourcing
+    if grep -q "^[[:space:]]*[^#][^=]*=" /app/data/.env 2>/dev/null; then
+        set -a  # automatically export all variables
+        if source /app/data/.env 2>/dev/null; then
+            echo "=> Custom .env file loaded successfully"
+        else
+            echo "=> Warning: Error loading .env file, using Cloudron defaults"
+            echo "=> Check /app/data/.env for syntax errors (values with spaces need quotes)"
+        fi
+        set +a  # stop automatically exporting
+    else
+        echo "=> Warning: /app/data/.env appears to be empty or invalid, using Cloudron defaults"
+    fi
 else
     echo "=> No custom .env file found, using Cloudron defaults"
 fi