Sendmail 配置文件如下：

　　/etc/mail/sendmail.mc

　　dnl #

　　dnl # This is the sendmail macro config file for m4. If you make changes to

　　dnl # /etc/mail/sendmail.mc, you will need to regenerate the

　　dnl # /etc/mail/sendmail.cf file by confirming that the sendmail-cf package is

　　dnl # installed and then performing a

　　dnl #

　　dnl # make -C /etc/mail

　　dnl #

　　include(`/usr/share/sendmail-cf/m4/cf.m4′)dnl (将sendmail-cf/m4/cf.m4包含进来)

　　VERSIONID(`setup for Red Hat Linux’)dnl (定义版本信息)

　　OSTYPE(`linux’)dnl (选择包含操作系统指定属性的文件)

　　dnl #

　　dnl # default logging level is 9, you might want to set it higher to

　　dnl # debug the configuration

　　dnl #

　　dnl define(`confLOG_LEVEL’, `9′)dnl

　　dnl #

　　dnl # Uncomment and edit the following line if your outgoing mail needs to

　　dnl # be sent out through an external mail server:

　　dnl #

　　dnl define(`SMART_HOST’,`smtp.your.provider’)

　　dnl #

　　define(`confDEF_USER_ID’,“8:12”)dnl (指定使用的用户ID为8，组ID为12)

　　dnl define(`confAUTO_REBUILD’)dnl

　　define(`confTO_CONNECT’, `1m’)dnl (设置等待连接的最大时间为1分钟)

　　define(`confTRY_NULL_MX_LIST’,true)dnl (若MX记录指向本机，则sendmail直接连接到远程主机)

　　define(`confDONT_PROBE_INTERFACES’,true)dnl (sendmial不会自动将服务器的网络接口视为有效地址)

　　define(`PROCMAIL_MAILER_PATH’,`/usr/bin/procmail’)dnl(设置procmail的存放路径)

　　define(`ALIAS_FILE’, `/etc/aliases’)dnl (设置邮件别名存放路径)

　　define(`STATUS_FILE’, `/var/log/mail/statistics’)dnl

　　define(`UUCP_MAILER_MAX’, `2000000′)dnl (设置处理信息的最大限制为2M)

　　define(`confUSERDB_SPEC’, `/etc/mail/userdb.db’)dnl (设置用户数据库文件路径)

　　define(`confPRIVACY_FLAGS’, `authwarnings,novrfy,noexpn,restrictqrun’)dnl (设置限制某些邮件命令的标志)

　　define(`confAUTH_OPTIONS’, `A’)dnl 仅在授权成功时。将AUTH参数加到邮件的消息头中

#p#

　　dnl #

　　dnl # The following allows relaying if the user authenticates, and disallows

　　dnl # plaintext authentication (PLAIN/LOGIN) on non-TLS links

　　dnl #

　　dnl define(`confAUTH_OPTIONS’, `A p’)dnl

　　dnl #

　　dnl # PLAIN is the preferred plaintext authentication method and used by

　　dnl # Mozilla Mail and Evolution, though Outlook Express and other MUAs do

　　dnl # use LOGIN. Other mechanisms should be used if the connection is not

　　dnl # guaranteed secure.

　　dnl # Please remember that saslauthd needs to be running for AUTH.

　　dnl #

　　dnl TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN’)dnl

　　dnl define(`confAUTH_MECHANISMS’, `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN’)dnl

　　dnl #

　　dnl # Rudimentary information on creating certificates for sendmail TLS:

　　dnl # cd /usr/share/ssl/certs; make sendmail.pem

　　dnl # Complete usage:

　　dnl # make -C /usr/share/ssl/certs usage

　　dnl #

　　dnl define(`confCACERT_PATH’,`/usr/share/ssl/certs’)

　　dnl define(`confCACERT’,`/usr/share/ssl/certs/ca-bundle.crt’)

　　dnl define(`confSERVER_CERT’,`/usr/share/ssl/certs/sendmail.pem’)

　　dnl define(`confSERVER_KEY’,`/usr/share/ssl/certs/sendmail.pem’)

　　dnl #

　　dnl # This allows sendmail to use a keyfile that is shared with OpenLDAP’s

　　dnl # slapd, which requires the file to be readble by group ldap

　　dnl #

　　dnl define(`confDONT_BLAME_SENDMAIL’,`groupreadablekeyfile’)dnl

　　dnl #

　　dnl define(`confTO_QUEUEWARN’, `4h’)dnl

　　dnl define(`confTO_QUEUERETURN’, `5d’)dnl

　　dnl define(`confQUEUE_LA’, `12′)dnl

　　dnl define(`confREFUSE_LA’, `18′)dnl

　　define(`confTO_IDENT’, `0′)dnl

　　dnl FEATURE(delay_checks)dnl

一口气看完sendmail的配置文件，那就不简单了，我会在后面文章给大家介绍下半部分。