smtplib.SMTPDataError: (550, b'5.7.60 SMTP; Client does not have permissions to send as this sender

The Email Accounts & Domain are set and saved without any Errors but when i try to add new user, the confirmation email cant be sent and i got the that error “in the tittle above”.
Even when i manually from the users tap “CTRL+E” sent an email to the user, it does not sent any emails.

Error Detail:

App Versions

{
	"erpnext": "14.25.1",
	"frappe": "14.36.3"
}

Route

Form/User/new-user-2

Traceback

Traceback (most recent call last):
  File "apps/frappe/frappe/app.py", line 66, in application
    response = frappe.api.handle()
  File "apps/frappe/frappe/api.py", line 54, in handle
    return frappe.handler.handle()
  File "apps/frappe/frappe/handler.py", line 45, in handle
    data = execute_cmd(cmd)
  File "apps/frappe/frappe/handler.py", line 83, in execute_cmd
    return frappe.call(method, **frappe.form_dict)
  File "apps/frappe/frappe/__init__.py", line 1607, in call
    return fn(*args, **newargs)
  File "apps/frappe/frappe/client.py", line 229, in save
    doc.save()
  File "apps/frappe/frappe/model/document.py", line 305, in save
    return self._save(*args, **kwargs)
  File "apps/frappe/frappe/model/document.py", line 327, in _save
    return self.insert()
  File "apps/frappe/frappe/model/document.py", line 285, in insert
    self.run_post_save_methods()
  File "apps/frappe/frappe/model/document.py", line 1082, in run_post_save_methods
    self.run_method("on_update")
  File "apps/frappe/frappe/model/document.py", line 914, in run_method
    out = Document.hook(fn)(self, *args, **kwargs)
  File "apps/frappe/frappe/model/document.py", line 1264, in composer
    return composed(self, method, *args, **kwargs)
  File "apps/frappe/frappe/model/document.py", line 1246, in runner
    add_to_return_value(self, fn(self, *args, **kwargs))
  File "apps/frappe/frappe/model/document.py", line 911, in fn
    return method_object(*args, **kwargs)
  File "apps/frappe/frappe/core/doctype/user/user.py", line 122, in on_update
    self.send_password_notification(self.__new_password)
  File "apps/frappe/frappe/core/doctype/user/user.py", line 275, in send_password_notification
    self.send_welcome_mail_to_user()
  File "apps/frappe/frappe/core/doctype/user/user.py", line 346, in send_welcome_mail_to_user
    self.send_login_mail(
  File "apps/frappe/frappe/core/doctype/user/user.py", line 378, in send_login_mail
    frappe.sendmail(
  File "apps/frappe/frappe/__init__.py", line 711, in sendmail
    builder.process(send_now=now)
  File "apps/frappe/frappe/email/doctype/email_queue/email_queue.py", line 662, in process
    send_now and q.send()
  File "apps/frappe/frappe/email/doctype/email_queue/email_queue.py", line 142, in send
    ctx.smtp_session.sendmail(from_addr=self.sender, to_addrs=recipient.recipient, msg=message)
  File "/usr/lib/python3.10/smtplib.py", line 908, in sendmail
    raise SMTPDataError(code, resp)
smtplib.SMTPDataError: (550, b'5.7.60 SMTP; Client does not have permissions to send as this sender')

Request Data

{
	"type": "POST",
	"args": {
		"doc": "{\"docstatus\":0,\"doctype\":\"User\",\"name\":\"new-user-2\",\"__islocal\":1,\"__unsaved\":1,\"owner\":\"Administrator\",\"enabled\":1,\"language\":\"de\",\"send_welcome_email\":1,\"unsubscribed\":0,\"desk_theme\":\"Light\",\"mute_sounds\":0,\"logout_all_sessions\":1,\"document_follow_notify\":0,\"document_follow_frequency\":\"Daily\",\"follow_created_documents\":0,\"follow_commented_documents\":0,\"follow_liked_documents\":0,\"follow_assigned_documents\":0,\"follow_shared_documents\":0,\"thread_notify\":1,\"send_me_a_copy\":0,\"allowed_in_mentions\":1,\"simultaneous_sessions\":1,\"user_type\":\"System User\",\"bypass_restrict_ip_check_if_2fa_enabled\":0,\"__run_link_triggers\":1,\"email\":\"user@email.de\",\"first_name\":\"user2firstname\",\"last_name\":\"user1lastname\"}"
	},
	"freeze": true,
	"headers": {},
	"error_handlers": {},
	"url": "/api/method/frappe.client.save"
}

Response Data

{
	"exc_type": "DoesNotExistError",
	"exception": "smtplib.SMTPDataError: (550, b'5.7.60 SMTP; Client does not have permissions to send as this sender')"
}