mail/bulk_mailer 1.13nb1 NetBSD

bulk_mailer assists with "bulk" mailing, such as large majordomo lists under sendmail. For input, it takes a file of recipient addresses (one address per line) and a message (with headers already attached) to be sent to the recipients. It sorts the recipient list by reversed domain (so similar ones sort together), splits up the recipients into several groups containing no more than N domains each, creates an SMTP envelope for each group of recipients, and feeds that envelope to "/usr/lib/sendmail -bs".

Splitting the envelopes up allows sendmail to perform delivery in parallel, so instead of having one large queue entry (for which sendmail might take awhile to get around to attempting delivery for some recipients), it has several smaller queue entries. Depending on your point-of-view, this can still be considered "cluttering up your mail queue", but it does seem to deliver messages more quickly to most recipients.