[unisog] Email for life
prussell at nd.edu
Tue Mar 23 15:27:49 GMT 2004
Daniel Feenberg wrote:
> 1) Reject spam and virus traffic during the SMTP transaction, rather than
> discarding mail later, or (worse) generating DSN mail. This isn't an easy
> ability to find - Can-it is the only such package I am aware of for
> Sendmail. Spamassassin could be run within a milter to do this, if you
> have the skills.
Sendmail can be configured to reject, at the SMTP level, messages for recipient
addresses which cannot be resolved via LDAP lookups.
> 2) Reject mail to overquota mailboxes. Note that if you offer pop service,
> sendmail (strictly speaking, the sendmail local delivery agent mail.local)
> can't do this right, since once the mailbox is more than half full, pop
> can't make a working copy of mailbox without busting the quota, and
> therefore won't allow the user to process his mail (including deleting
This is dependent on the structure of the mailstore. If individual messages are
stored as discrete files, rather than appended to a monolithic mbox file, the
'more than half full' problem is easily addressable. Several mailstore products,
including some open source products, provide this capability.
> There is an "FSTAT" patch for sendmail that could probably be
> modified to make sendmail respect quotas in a practical way
If the MX service and the mailstore reside on the same server, this might
be possible. If they reside on separate servers, the problem becomes more
> or procmail
> could be so programmed (but that wouldn't happen during the SMTP
> transaction, so you would be sending DSNs for overquota messages, many
> of which would be going to forged return addresses). Perhaps other MTAs
> are better at this.
Senior Systems Administrator
University of Notre Dame
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