Hi,

Thanks for your help. i did find a file named maillog in /var/adm which contains all the mails sent by the unix server for a day.

The maillog has records like this-
May 5 08:30:41 nus220 sendmail[29817]: k44MUbM29801: to=miamikool@otherplace.com, ctladdr=kndsep (40105/40025), delay=00:00:04, xdelay=00:00:03, mailer=relay, pri=121651, relay=cdn-mail.somewhere.com.au. [10.10.138.138], dsn=2.0.0, stat=Sent (IAA03690 Message accepted for delivery)

Does the last part stat=Sent (IAA03690 Message accepted for delivery) mean that the msg has gone successfully?

Also i tried the command /usr/lib/sendmail -d0.1 -bt < /dev/null as suggested and got the following output:
-------------------------------------------------------------------
Version 8.11.6+Sun
Compiled with: LDAPMAP MAP_REGEX LOG MATCHGECOS MIME7TO8 MIME8TO7
NAMED_BIND NDBM NETINET NETINET6 NETUNIX NEWDB NIS NISPLUS
QUEUE SCANF SMTP USERDB XDEBUG

============ SYSTEM IDENTITY (after readcf) ============
(short domain name) $w = nus220
(canonical domain name) $j = nus220.in.somewhere.com.au
(subdomain name) $m = somewhere.com.au
(node name) $k = nus220

ADDRESS TEST MODE (ruleset 3 NOT automatically invoked)
Enter <ruleset> <address>
----------------------------------------------------------------------

i dont really understand what it means? could you help me with this?

Also i would like to know how does mailx work internally? as in does it store the mails in a buffer before sending it? and what happens if the mail is not sent? where does that mail go if it was not sent successfully?

Thanks for the help in advance.