The sendmail service is a program that acts as a mail transfer agent. The sendmail program is responsible for receiving email messages from user agents and delivering them to local delivery agents. The Oracle Solaris operating system (OS) supplies standard configuration files for sendmail. The sendmail program uses the configuration files to provide aliasing, forwarding, automatic routing to network gateways, and flexible configuration.
The Oracle Solaris OS uses the sendmail program as a mail router. The Oracle Solaris version of sendmail has the following features:
Delivers messages accurately without any data loss using communications protocols, such as TCP/IP. It implements an SMTP server, message queuing, and mailing lists. This program can be configured to handle complex environments including multiple networks. It also checks the contents of an address and its syntax to determine which mailer to use.
Uses existing software for delivery whenever possible. You do not need to install additional software to perform a task. For example, the sendmail program works interactively and manages both the mail-generating and the mail-sending program. When you send a mail, the mail-generating program calls sendmail, which routes the message to the correct mailers. Because some senders are network servers and some mailers are network clients, sendmail can be used as an Internet mail gateway. For more information, see How sendmail Works With Programs.
Uses configuration files to control mail configuration. You do not need to compile the configuration information in the code of the sendmail program. The program enables you to use different configuration files for different environments. For example, the Oracle Solaris OS provides a default configuration file for the sendmail program. Create a backup of the default configuration file before you modify the file according to your environment. The modified configuration file is tested and then used. The sendmail program enables you to create many such configuration files for many environments without having to lose the default configuration file. For more information, see sendmail Configuration File.
Can be configured to automatically rebuild the sendmail.cf and the submit.mc configuration files. For more information, see Automatically Rebuilding Configuration Files.
The sendmail program controls name interpretation by using a pattern-matching system that works with the following naming conventions:
Domain-based naming convention. The domain technique distinguishes physical naming from logical naming
Improvised techniques, such as providing network names that appear local to hosts on other networks
Arbitrary (older) naming syntaxes
Disparate naming schemes
The sendmail program controls email messages that users send in the following ways:
Evaluates the recipients' addresses
Chooses an appropriate delivery program
Rewrites the addresses in a format that the delivery agent can handle
Reformats the mail headers as required
Passes the transformed message to the mail program for delivery
For more information, see Rerouting Mechanisms and sendmail Configuration File.
The following changes have been made in the Oracle Solaris 11.3 release:
The default version of sendmail was updated to 8.15.1.
Mailman Mailing List Manager is integrated to manage email discussions and e-newsletter lists.
This section describes some of the differences in the Oracle Solaris version of sendmail as compared to the generic Berkeley version.
To see a list of the flags that are used to compile sendmail, use the following command:
% /usr/lib/sendmail -bt -d0.10 < /dev/null
This command does not list the flags that are specific to Oracle Solaris.
If your configuration requires other flags, you need to download the source and recompile the binary. For more information, see Compiling Sendmail (https://web.archive.org/web/20161025083736/http://www.sendmail.com:80/sm/open_source/tips/compiling_sendmail/).
The following flags are used when compiling the sendmail binary.
Support for the Oracle Solaris 11 release.
Support for the Mail Filter API. In version 8.13 and later versions of sendmail, this flag is enabled by default.
Support for IPv6. This flag has been moved from conf.h to Makefile.
MILTER, sendmail's Mail Filter API, enables third-party programs to access mail messages as they are being processed to filter meta-information and content. You do not need to build the filter and configure sendmail to use it. This API is enabled by default in version 8.13 of sendmail.
The following OS-specific compile flags are used when building the sendmail library.
Support for various Oracle Solaris added extensions that are included in sun_compat.o.
For backward compatibility, support for the use of NIS domain names to fully qualify the local host name.
Support for a simplified LDAP API, which is specific to Oracle Solaris.
Selects Oracle Solaris as the default vendor.
The following generic flag is not used to compile the version of sendmail.
Oracle Solaris does not include all the command synonyms that are provided in the generic release from the Open Source sendmail organization. The following table provides information about the command aliases.
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