...

Can I send this email via SMTP server?

You don't.

You would have had to gone to some effort to not have an MTA installed, as one is installed by default. Did you remove it (or simply not configure it)? [they basically work for localhost delivery without any changes.]

CentOS 6 64 bit, zimbra is running with multi server setup. One mailbox and 2 mta servers.

on mailbox server where no mta is installed, I want to backup mailboxes with a script. I have set it up to /etc/cron.d/backup file. After the backup, I want to an email to be sent to admin account.

for the moment, I get an OUTPUT in this way. ( my /etc/cron.d/backup looks like this )

35 13 * * * root /root/scripts/backup.sh > /tmp/backup.out 2>&1

I always login to the mailbox server and see the OUTPUT which is NOT so PERFECT.

You can't deliver to an "SMTP server" as, without an MTA, you have no (real) way to talk to it.

thanks for it.