Frappe.sendmail does not send a cc to the same thread

Hi everyone,

I’m sending emails to employees on their birthdays and work anniversaries

The birthday person and ‘teams’ should receive emails. If I add cc to frappe.sendmail, mails are sent to recipients and cc separately. My goal is to send both of them in the same thread.

def send_birthday_reminders_custom():
“”“Send Employee birthday reminders if no ‘Stop Birthday Reminders’ is not set.”“”
to_send = int(frappe.db.get_single_value(“HR Settings”, “send_birthday_reminders”))

if not to_send:

employees_born_today = get_employees_who_are_born_today()

for company, birthday_persons in employees_born_today.items():        
    for person in birthday_persons:
        if person['status'] in ['Active', 'Left']:
            cc = [''] if person['status'] == 'Active' else ['']
            birthday_person_names = person['name']
            recipients = [person['company_email']]
            message = get_birthday_reminder_text_and_message(person)
            frappe.sendmail(recipients = recipients,cc = cc,subject=f"Happy Birthday {person['name']}",message = message,expose_recipients = True,)

expose_recipients = ‘header

				expose_recipients = 'header',