@sreenivasK1292 

I have tried the below approach please find this navigation.

Step 1: Create the edit validate rule.

Step 2: insert the given sample java code (for code find below code)

if (theProperty != null) {   String value = theProperty.toString();

  if (!value.matches("^[a-zA-Z][a-zA-Z0-9._]*[a-zA-Z0-9]@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$")) {     theProperty.addMessage("Invalid email: It must start with a letter, end with a letter or number, and be in a valid format.");     return false;   } } return true;

Step 3: call custom rule in the use validate in the property (advanced tab)

OR

Step 4: You can call this edit validate rule in the validate rule.

I have validated below email id:

• [email protected] → ✅

• [email protected] → ✅

• [email protected] → ❌ (starts with number)

• [email protected] → ❌ (starts with dot)

• [email protected] → ❌ (ends with dot)

• @[email protected] → ❌ (start with special character)