canonical name in DNS

[Essy Ren]

When I follow the config command to configure the qmail, it's say something like this :   ./config Your hostname is sanfransisco. hard error Sorry, I couldn't find your host's canonical name in DNS. You will have to set up control/me yourself.   And here's is my DNS setting :   $TTL 86400 erakarsa.local. IN SOA sanfransisco.erakarsa.local. essy.erakarsa.local. (                 1       ; Serial                 10800   ; Refresh after 3 hours                 3600    ; Retry after 1 hour                 604800  ; Expire after 1 week                 14400 ); Minimum TTL of 1 day   erakarsa.local. IN NS sanfransisco.erakarsa.local.   localhost.erakarsa.local.       IN      A       127.0.0.1 koni.erakarsa.local.            IN      A       192.168.1.23   erakarsa.local.                 IN      MX      10 mail.erakarsa.local. mail.erakarsa.local.            IN      A       192.168.1.23   Can you help me ....