EMBEDDED_MAIL_MERGE

This configuration variable determines whether LISTSERV writes individual mail-merge messages to its spool, or uses BSMTP to offload the creation of the individual messages to an external server. With embedded mail-merge, any high-capacity SMTP server can be used to deliver LISTSERV email that uses mail-merge.

Embedded mail-merge is a brute-force method. In this mode, each individual merged message is written to the LISTSERV spool as a single-recipient MAIL file. In turn, each individual MAIL file is then delivered by SMTP to the outbound SMTP_FORWARD host.

Since Batch SMTP (BSMTP) cannot be used in the embedded mode, sites with very high volumes of mail may wish to split the load across multiple outbound mail servers using SMTP workers (defined with SMTP_FORWARD_N). In addition, Distribute workers can be used in very high volume situations to move mail smoothly.

The default value is 1 (enabled).