sendmail mail pool?

/var/spool/clientmqueue

sendmail mail pool?


The following message is copied from forum

> Hi, all
>   I found there is a directory named /var/spool/clientmqueue and many
> many file below this directory, what's use of this directory and the
> files under it?
>   thanks.

When submitting mail by using sendmail as a mail submission program,
sendmail copies all messages to /var/spool/clientmqueue first. sendmail is
a setgid smmsp program and thus gives the any user the permission to do so
(/var/spool/clientmqueue belongs to user and group smmsp).

Later, another sendmail process, the sendmail localhost-only (FreeBSD
default config) mail transfer agent (MTA) copies the messages from
/var/spool/clientmqueue to /var/spool/mqueue and sends them to their
destination.

When files accumulate in /var/spool/clientmqueue, you probably don't run
the sendmail localhost MTA, and thus the mails don't get send.