Under the 'Home' tab, click on the Junk dropdown.
Click on the 'Junk E-mail Options...' link.
Select the 'Blocked Senders' tab and make sure that 'E_ATP_2022_Conference@mail.vresp.com' is not listed. If it is, select it and remove it from the list.
Select the 'Safe Senders' tab, then click the 'Add...' button. Enter the domain, '@mail.vresp.com' and click the 'OK' button.