Nop, no connection at all.
But if I send a mail directly from thunderbird to the mail which shows the error it works fine.
0F78F6916153: to=<p***@w***.com>, relay=***.mail.protection.outlook.com[IP]:25, delay=2.1, delays=0.54/0.02/0.19/1.4, dsn=2.6.0, status=sent (250 2.6.0...