1. LISTSERV requires one of the Microsoft Windows operating systems listed in the matrix found in the Preface to this manual.
    2. Either Internet Information Service (IIS) or some other WWW server (i.e., Apache) should be installed on the machine if you intend to use the web archive and administration interface.  LISTSERV's web interface cannot be installed on a separate machine.  If you are using an older version of IIS which includes the IIS SMTP service, IIS SMTP should be disabled or not installed unless you intend to use it for inbound and outbound mail (in which case, please contact L-Soft support to receive a white paper describing how to do this).
    3. INBOUND MAIL: The SMTP "listener" service (SMTPL.EXE) provided in the LISTSERV installation kit must be installed.  Third-party SMTP MTAs (Mail Transfer Agents) are supported for inbound LISTSERV mail if they can be configured to redirect LISTSERV's mail to SMTPL running on a non-standard "high" port (for instance, 40025).

Note:  L-Soft's legacy LSMTP mailer is no longer supported in any way.  While sites with valid licenses for L-Soft's legacy LSMTP mailer may of course continue to use LSMTP for both inbound and outbound mail, L-Soft strongly discourages the use of this discontinued, no longer supported product.  We will be happy to discuss alternatives with you; please simply write to support@lsoft.com and request details.
    1. OUTBOUND MAIL:  The SMTPL.EXE "listener" service cannot be used for outbound mail.  You will need to have access to an SMTP MTA that can handle LISTSERV's outbound mail. This machine can be a unix machine running one of the standard unix MTAs (sendmail/qmail/postfix), a Windows machine running Microsoft Exchange, or any fully-standards-compliant SMTP server running on any platform, as long as it can handle the amount of traffic you will generate with LISTSERV.

Low-end SMTP servers can handle modest delivery loads (perhaps 10K-25K messages per hour, although we have seen a well-tuned IIS SMTP instance handle up to 75K per hour). For heavier delivery loads, L-Soft recommends a high-performance SMTP server that can handle loads of more than 1 million messages per hour.

If the outbound MTA is running on an external machine, that machine must be configured to accept for delivery so-called "relay mail" from the machine running LISTSERV (it may of course otherwise be configured to reject "relay mail" coming from other hosts).

Please note the following for both inbound and outbound mail:


  • LISTSERV does not have the capability of accessing a remote mailbox for its inbound mail.  LISTSERV does not understand POP or IMAP or any other mail retrieval protocol.  All mail coming in to LISTSERV must arrive via SMTP.
  • LISTSERV cannot connect directly to an SMTP server that requires SMTP AUTH on the outbound side.  If you cannot arrange an exception for the LISTSERV server such that it is not required to authenticate to the outbound SMTP server, you will have to use an intermediary method to offload the outbound mail.  Typically, the IIS SMTP server mentioned above can be used to solve this problem.
  • LISTSERV does not do STARTTLS on either the outbound or inbound side.  If you have a requirement for STARTTLS, please see https://lsoft.com/manuals/lsv-faq/447SMTPTLSandLISTSERV.html for a discussion of a possible solution.