Если:

# less /service/qmail-smtp-ssl/log/main/current

 видим такое:

sslserver: fatal: unable to load CA list

 то переустанавливаем:

# cd /usr/ports/security/ca_root_nss/

# make config

[X] ETCSYMLINK  Add symlink to /etc/ssl/cert.pem

# make install clean FORCE_PKG_REGISTER=yes