Help: Auto-assign inbound email replies to Lead owner via Group mailbox

I have a sales process in SuiteCRM:

  1. A sales user creates a Lead and sends an email to the lead’s contact using a Group mailbox (e.g., sales@example.com).
  2. The contact replies, and the reply lands in the group mailbox.

What I need:

  • Automatically link the reply to the related Lead record.
  • Automatically assign the email to the Lead’s creator (or a user who has access to that Lead).

What I’ve done so far:

  • Successfully implemented inbound and outbound emails (Personal and Group mailboxes).
  • Enabled “Import emails automatically” on the Group mailbox.
  • “Create Case from Email” is disabled.
  • Attempted to use a Workflow rule, but it can’t look up the related Lead record’s owner (I cannot find any related topics or documents how to implement and debug such cases)
  • Found suggestions to use custom logic hooks, but no clear code examples. I prefer not to use code for such straight forward process.

Request:

  1. could anyone share a same experience with me and tell me how to do that step by step.
  2. Is that necessary to implement a workflow for such scenarios? Why auto import cannot handle such cases!?
  3. if writing a custom logic hooks is the best option, can someone show me an example code?

Thanks in advance!