This article details how to implement Okta Expression Language to manage email aliases in scenarios where a user needs to access multiple instances of an application, each instance demanding a unique email address. This instruction will elucidate each part of the expression, explaining its role and effect.

• Okta administrators
• Developers managing distinct instances of an application 
• Developers handling unique email addresses for users across distinct instances

Certain applications recognize users through their email addresses as a unique identifier. Even if these applications have different instances, they might consider the same email address across these instances as a duplicate, thus raising conflicts.

1. An email admin should initially establish an email alias for every user requiring access to several instances, ensuring that the application does not recognize the user as a duplicate.

2. Apply the following Okta Expression Language conditional expression to the custom application username format:

   isMemberOfGroupName("sample") ? (substringAfter(substringBefore(Arrays.toCsvString(user.proxyAddressess), ','), "smtp:")) : user.login.

   
    

The above conditional expression is broken down as follows:

• • isMemberOfGroupName("sample")
    This function checks whether the user is part of the group named "sample". The resulting value is Boolean (true or false). 

  • ?:
    This is the ternary operator that initiates the action depending on the condition's result. 

  • (substringAfter(substringBefore(Arrays.toCsvString(user.proxyAddressess), ','), "smtp:"))
    If the user is part of the "sample" group (true condition), this function is executed. It takes the proxyAddress mapped from Active Directory to the Okta User Profile, converting it to a CSV string. The function then captures the substring before the first comma (','), and from this substring, it extracts the portion after "smtp:".

  • :
    This operator separates the values that the ternary operator will return depending on the condition's evaluation.

  • user.login
    If the user is not part of the "sample" group (false condition), the function will return the user's login username.

With this conditional expression, members of a specific group (for example, managers) can use the email alias, while regular users can use their standard email address.

NOTE: Formatting issues might interfere with the expression's functionality, so it's essential to validate its operation by testing with different user accounts.
 

Related References

• Okta Expression Language - Conditional expressions