Man pages matching name virt_mail in section 1:

VIRT_MAIL.1.en	debian 10 / virtuoso-opensource-6.1-bin
virt_mail.1.en	debian 10 / virtuoso-opensource-6.1-bin
VIRT_MAIL.1.en	debian 11 / virtuoso-opensource-7-bin
virt_mail.1.en	debian 11 / virtuoso-opensource-7-bin
VIRT_MAIL.1.en	debian 12 / virtuoso-opensource-7-bin
virt_mail.1.en	debian 12 / virtuoso-opensource-7-bin