Workday → Okta user email creation best practice

Hello everyone,

We recently migrated our HRIS to Workday, and I’m looking for advice / best practices around user email (work email) creation, especially when handling duplicate names.

Background

Before Workday, our flow was:

Old HRIS → custom app/code → Okta

That custom code handled email uniqueness logic. For example:

  • If two users had the same first + last name (e.g., John Doe),

  • The second user’s email would automatically include a middle initial or similar logic to prevent duplicates.

Current Okta setup

In Okta:

  • login == email (work email)
    Example:
    login: john.doe@company.com
    email: john.doe@company.com

However, we also have legacy users created years ago with formats like:

  • login: jdoe@company.com

  • email: jdoe@company.com

Concern

If we move to Workday-driven provisioning, I’m concerned that:

  • Existing users with legacy usernames/emails might be impacted

  • Or that we’ll run into conflicts when Workday creates new users with duplicate names

Big question

With Workday as the HR source of truth:
Who should be responsible for creating the work email?

  • Workday?

  • Okta?

  • Or some external logic (Workflows, middleware, etc.)?

What I’ve found so far

  • Okta Expression Language doesn’t seem great at handling email uniqueness at scale (especially for first + last name collisions).

  • Our Workday team claims they cannot generate the work email in Workday — which I’m skeptical about, since I’ve heard from others that this is possible (likely via calculated fields or business processes).

  • Unfortunately, Workday documentation isn’t public, so it’s hard to verify independently.

What I’m hoping to learn

  • Have any of you dealt with this exact problem?

  • Do you generate the email in Workday, Okta, or elsewhere?

  • How do you safely handle:

    • Duplicate names

    • Legacy users

    • login == email constraints in Okta

Any real-world experience or architectural guidance would be greatly appreciated. Thanks in advance!