You're an accountant in a small tax firm and need to notify an important client that the ATO will be auditing their previous financial year's tax return. The ATO has requested additional supporting information (invoices, bank statements, etc.) and you'd appreciate them submitting documents X, Y & Z to you by X date. follow-up email to your client:

explain the situation

request the documentation (X, Y & Z)

outline deadlines (X date)

pay attention to email structure, tone, grammar and vocabulary