SENDQ Utility

Updated May 19, 1997


SENDQ is designed for use with Post.Office, an SMTP server for Microsoft Windows NT® from Software.Com (obviously, It's designed for forcing a mail dump when the primary SMTP server is using on-demand dialing in the following scenario:

  • There is a domain that has an infrequent connection to the Internet or an intranet via an on-demand router.
  • The SMTP server that the domain uses gets its email primarily from mail dumps from another SMTP server up the MX chain.
  • This SMTP server is running Windows NT 3.51 or later
  • The secondary server (i.e. the one permanently connected to the Internet or an intranet) is running Post.Office or understands the QSND command.
What It Does SENDQ simply opens a connection to the secondary SMTP server and sends it a QSND command for the domain specified. If any mail is being held by the secondary server (because it couldn't be delivered, because the line was down) it will be delivered.
How It Works

SENDQ relies on an on-demand dialer being present at the remote site, so that when SENDQ runs, the dialer will open the connection to the network containing the secondary server (usually an ISP or an intranet site). When the secondary server gets the QSND message, the traffic generated as a result of any mail dump will cause the router to keep the line open.

After the mail dump has completed or if there was no pending mail on the secondary server, the line will drop based on the timeout set in the on-demand router.

Of course, if the router is already connected to the Internet or an intranet because of existing traffic (which entails that mail would be delivered to the primary MX host anyway), SENDQ will have no effect.


Just copy the 'sendq.exe' file to the \winnt\system32 folder and then use the Windows NT 'at' command to schedule times throughout the day that you want to poll for SMTP email. Also recommended is the graphical 'winat' command that's part of the Windows NT Resource Kit.

You can also use SENDQ at any time from any PC on the remote network. This will force an immediate mail dump by running it from the command line.


SENDQ is very simple to use. It needs to know the hostname or IP address of the secondary SMTP server and the domain-name to dump email for:

sendq secondary-mail-server domain

For example:



SENDQ is provided as "freeware" without charge. It may be used freely on any system for its defined purpose subject to the following conditions:

  1. It is supplied "as-is" and without warranty
  2. COOL.STF cannot be held responsible for any loss or damages relating from the use of this program
  3. In case of any loss or damages as a result of the use of this program, you agree not to sue COOL.STF or it's suppliers.
  4. COOL.STF cannot answer support questions on this utility. If you have problems, they are most probably related to your SMTP, DNS, or IP configuration. Try one of the Usenet groups dealing with these topics.