This is the mail system at host lists.oulu.fi.

I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can delete your own text from the attached returned message.

The mail system

vratas@oulu.fi: host oulu-fi.mail.protection.outlook.com[52.101.73.11] said: 550 5.4.1 Recipient address rejected: Access denied. For more information see https://aka.ms/EXOSmtpErrors [AM3PEPF0000A78E.eurprd04.prod.outlook.com 2026-02-10T07:43:23.681Z 08DE6855979E54F6] (in reply to RCPT TO command)