Introducing Sendmail for MPE/iX 7.5

By Mark Bixby, Commercial Systems Division

Previously available as unsupported freeware, Sendmail is now bundled into MPE/iX 7.5 FOS as a fully supported product, which allows you to send and receive SMTP-based e-mail. The initial A.01.00 release of Sendmail for MPE/iX is based on the 8.12.1 Internet open source version from sendmail.org.

System Requirements and Patches

Sendmail has the following prerequisites:

MPE/iX 7.5 Release.
HP highly recommends installing the latest NSTxxxxx network transport patch.
Syslog/iX configured and running so that Sendmail can log warnings, errors, and message traffic data. Syslog/iX is documented in the Configuring and Managing MPE/iX Internet Services manual.
Your HP e3000 must be configured to use one or more DNS servers, and must have the correct entries in the DNS database corresponding to the configured hostname in :NMMGR. See "DNS Issues" for more detail.
Any network firewalls, routers, or switches that your HP e3000 communicates with must be configured to allow your HP e3000 to send and receive packets on port 25 (SMTP) and port 53 (DNS). See "Firewall Issues" for more detail.

Support

Sendmail 8.12.1 for MPE/iX is supported through the HP Response Center as part of MPE/iX FOS support.

Product Overview and Feature Set

The feature set of Sendmail for MPE/iX is quite extensive; the following is only a partial list:

Send and receive SMTP-based e-mail from sessions and/or batch jobs
Deliver local e-mail to mailboxes, files, or programs
A vast selection of tunable performance parameters
Highly flexible and extremely powerful configuration language
Access control for accepting or rejecting incoming e-mail
Message header rewriting capabilities
Modular feature set allows you to configure exactly the functionality you want; the following optional features have been configured by default in this distribution:
- access_db
- domaintable
- genericstable
- mailertable
- virtusertable
Open-source robustness and reliability
Compatibility with the HP-UX Sendmail file layout

DNS Issues

The number one cause of Sendmail installation problems is due to improper system naming and/or a lack of DNS entries describing your HP e3000. Please verify the following before you attempt to run Sendmail for the first time:

/bin/uname -n should report your HP e3000 hostname as a single token, i.e., "JAZZ" instead of "JAZZ.EXTERNAL.HP.COM". If you do not see a single token hostname, you must configure a proper hostname by using :NMMGR.
/SYS/NET/RESLVCNF must contain a single "domain" statement that defines the domain part of your HP e3000's fully qualified hostname. For example, /bin/uname -n should display "JAZZ" and /SYS/NET/RESLVCNF should contain a "domain external.hp.com" statement.
/SYS/NET/RESLVCNF must contain one or more "nameserver" statements which specify one or more DNS server IP addresses that your HP e3000 will be querying to resolve host names. It is not necessary to run a DNS server such as BIND on your HP e3000 itself.
Your HP e3000 must be defined within the DNS nameserver databases as having a valid "A" record that maps the HP e3000's hostname to an IP address.
Your HP e3000 must be defined within the DNS nameserver databases as having a valid "PTR" record that maps the HP e3000's IP address to a hostname.

Sendmail for MPE/iX is distributed with a convenient script that you can run to check all of the above DNS configuration issues and more:

:HELLO SERVER.SENDMAIL
:XEQ SH.HPBIN.SYS -L
shell/iX> /SENDMAIL/CURRENT/bin/dnscheck

The dnscheck script will instruct you how to fix any problems that it detects. After making each fix, keep rerunning the script until no more problems are found.

Firewall Issues

The number two cause of Sendmail installation problems is due to a firewall or other network security device blocking your HP e3000 from being able to send and receive packets on port 53 (DNS) and port 25 (SMTP).

Sendmail uses port 53 (DNS) to resolve hostnames into IP addresses and IP addresses into hostnames. Sendmail may do multiple DNS resolutions for every e-mail message sent or received, and if a firewall is blocking these DNS packets, Sendmail may experience long delays and/or generate various error messages logged to syslog.

Sendmail may need to contact external DNS servers if you are attempting to exchange e-mail with the Internet. Some intranet environments may require you to reference a "forwarding DNS server" (which can traverse your border firewall to talk to the Internet) via a nameserver statement in /SYS/NET/RESLVCNF. Consult your local network administrator for advice on how to choose a proper DNS server.

Port 25 (SMTP) is used to connect to remote mail servers to deliver outgoing e-mail, and is also used on the HP e3000 to listen for incoming e-mail. If a firewall is blocking outbound port 25 packets, Sendmail may experience long delays and generate various error messages logged to syslog as well as bounce messages returned to the e-mail originator. If a firewall is blocking inbound port 25 packets, Sendmail will not be able to receive any incoming e-mail, and there will be no extra syslog messages.

Migration from Sendmail 8.9.1

Many HP e3000 machines have been running the unsupported freeware version of Sendmail 8.9.1, available from http://www.bixby.org/mark/sendmailix.html. The following considerations apply if you are migrating from 8.9.1 to 8.12.1:

The 8.9.1 daemon job stream file /SENDMAIL/PUB/JDAEMON is not modified by the 8.12.1 installation process, and it is not compatible with the 8.12.1 distribution. You must use /SENDMAIL/CURRENT/JDAEMON.sample as a template for manually creating an 8.12.1-compatible /SENDMAIL/PUB/JDAEMON job stream file.
The 8.9.1 /SENDMAIL/PUB/SENDMAIL program file is renamed to SENDMAIL.bak and replaced by a symbolic link that points to the 8.12.1 /SENDMAIL/CURRENT/SENDMAIL program file. Any existing applications that refer to /SENDMAIL/PUB/SENDMAIL should continue to work properly without modification.
All 8.12.1 distribution files live in different HFS directories than the 8.9.1 distribution files. Once you are satisfied that 8.12.1 is working properly, you should purge the old 8.9.1 files to conserve disk space and avoid confusion.
All 8.12.1 configuration files reside in the /etc/mail directory instead of the old 8.9.1 location of /SENDMAIL/PUB/etc. The 8.9.1 sendmail.cf file is not compatible with 8.12.1, and so you will either have to use the default 8.12.1 /etc/mail/sendmail.cf file or create your own customized configuration file from the 8.12.1 configuration macros in /SENDMAIL/CURRENT/cf/cf.
All 8.9.1 database maps including the aliases file should be rebuilt using the 8.12.1 makemap or newaliases utilities.
Any undelivered messages still on the 8.9.1 queue will not be delivered by 8.12.1 which now has two separate queues residing at /var/spool/clientmqueue and /var/spool/mqueue instead of the previous single 8.9.1 queue location /SENDMAIL/PUB/mqueue.
The implementation of local message submission has changed with 8.12.1. Previously with 8.9.1, the /SENDMAIL/PUB/SENDMAIL program file would copy new messages from stdin directly into a queue disk file. With 8.12.1, the SENDMAIL program file will copy new messages from stdin and then contact the local HP e3000's port 25 to queue the messages using standard SMTP protocol.
8.12.1 does not include the Majordomo mailing list software that was bundled with 8.9.1.

For Further Information

Configuring & Managing MPE/iX Internet Services manual.
The HP CSY Sendmail web page of http://jazz.external.hp.com/src/sendmail/.
The official Sendmail web site of http://www.sendmail.org/.
Information about unsupported freeware versions of Sendmail for MPE/iX can be found at http://www.bixby.org/mark/sendmailix.html.
Documentation files installed on your local machine with this distribution:
- /SENDMAIL/CURRENT/doc/op/op.ps — Sendmail Installation and Operation Guide
- /SENDMAIL/CURRENT/cf/README — Sendmail Configuration Files
- /SENDMAIL/CURRENT/man — directory tree containing man page documentation, i.e.,:
  export MANPATH=/SENDMAIL/CURRENT/man:$MANPATH; man sendmail
The HP3000-L mailing list where you can talk with other users of Sendmail on MPE/iX:
- The official HP3000-L web site of http://raven.utc.edu/Archives/hp3000-l.html
- The gatewayed Usenet newsgroup of comp.sys.hp.mpe.