This is the mail system at host smtp3.osuosl.org.

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

aeckman@comporium.com: host comporium-com.mail.protection.outlook.com[52.101.11.9] said: 550 5.4.1 Recipient address rejected: Access denied. [SN1PEPF0002636A.namprd02.prod.outlook.com 2023-11-29T16:44:30.777Z 08DBED571D56D597] (in reply to RCPT TO command)