我需要从我的 Gmail 帐户向不同的收件人（很多）发送电子邮件，每个收件人的邮件内容相同，但附件不同。因此，我研究了命令行邮件客户端，并偶然发现了有关设置的教程为 Gmail 设置 sendmail。
我在“安装 sendmail”时遇到错误，并需要帮助。
辅助问题：如何将 sendmail.mc 重置为默认值（您下面看到的是从我在网上找到的复制粘贴的）？删除/安装 sendmail 不起作用。
# apt-get install sendmail sendmail-base sendmail-bin sendmail-cf sendmail-doc
Reading package lists... Done
Building dependency tree
Reading state information... Done
sendmail-base is already the newest version (8.15.2-3).
sendmail-base set to manually installed.
sendmail-bin is already the newest version (8.15.2-3).
sendmail-bin set to manually installed.
sendmail-cf is already the newest version (8.15.2-3).
sendmail-cf set to manually installed.
sendmail-doc is already the newest version (8.15.2-3).
The following additional packages will be installed:
procmail sensible-mda
Suggested packages:
rmail
The following NEW packages will be installed:
procmail sendmail sensible-mda
0 upgraded, 3 newly installed, 0 to remove and 7 not upgraded.
1 not fully installed or removed.
Need to get 0 B/151 kB of archives.
After this operation, 792 kB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Selecting previously unselected package procmail.
(Reading database ... 259644 files and directories currently installed.)
Preparing to unpack .../procmail_3.22-25ubuntu0.16.04.1_amd64.deb ...
Unpacking procmail (3.22-25ubuntu0.16.04.1) ...
Selecting previously unselected package sensible-mda.
Preparing to unpack .../sensible-mda_8.15.2-3_amd64.deb ...
Unpacking sensible-mda (8.15.2-3) ...
Selecting previously unselected package sendmail.
Preparing to unpack .../sendmail_8.15.2-3_all.deb ...
Unpacking sendmail (8.15.2-3) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up sendmail-bin (8.15.2-3) ...
Saving old /etc/mail/sendmail.cf as /etc/mail/sendmail.cf.old ...
Updating sendmail environment ...
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Writing configuration to /etc/mail/sendmail.conf.
Writing /etc/cron.d/sendmail.
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Writing configuration to /etc/mail/sendmail.conf.
Writing /etc/cron.d/sendmail.
Could not open /etc/mail/databases(No such file or directory), creating it.
Could not open /usr/share/sendmail-cf/m4/cf.m4(No such file or directory)
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Creating /etc/mail/databases...
Checking filesystem, this may take some time - it will not hang!
... Done.
Checking for installed MDAs...
Adding link for newly extant program (procmail)
sasl2-bin not installed, not configuring sendmail support.
To enable sendmail SASL2 support at a later date, invoke "/usr/share/sendmail/update_auth"
Creating/Updating SSL(for TLS) information
Creating /etc/mail/tls/starttls.m4...
You already have sendmail certificates
*** *** *** WARNING *** WARNING *** WARNING *** WARNING *** *** ***
Everything you need to support STARTTLS (encrypted mail transmission
and user authentication via certificates) is installed and configured
but is *NOT* being used.
To enable sendmail to use STARTTLS, you need to:
1) Add this line to /etc/mail/sendmail.mc and optionally
to /etc/mail/submit.mc:
include(`/etc/mail/tls/starttls.m4')dnl
2) Run sendmailconfig
3) Restart sendmail
Checking {sendmail,submit}.mc and related databases...
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Creating /etc/mail/databases...
Could not open /usr/share/sendmail-cf/m4/cf.m4(No such file or directory)
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Creating /etc/mail/databases...
Could not open /usr/share/sendmail-cf/m4/cf.m4(No such file or directory)
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Creating /etc/mail/Makefile...
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Writing configuration to /etc/mail/sendmail.conf.
Writing /etc/cron.d/sendmail.
Disabling HOST statistics file(/var/lib/sendmail/host_status).
Creating /etc/mail/sendmail.cf...
m4:/etc/mail/sendmail.mc:10: cannot open `/usr/share/sendmail-cf/m4/cf.m4': No such file or directory
Creating /etc/mail/submit.cf...
Informational: confCR_FILE file empty: /etc/mail/relay-domains
Informational: confCT_FILE file empty: /etc/mail/trusted-users
Informational: confUSERDB_SPEC file empty: /etc/mail/userdb.db
Updating /etc/mail/access...
Updating /etc/mail/authinfo/gmail...
Informational: mailertable file empty: /etc/mail/mailertable
Informational: use_ct_file file empty: /etc/mail/trusted-users
Informational: virtusertable file empty: /etc/mail/virtusertable
Updating /etc/aliases...
WARNING: local host name (yogurt) is not qualified; see cf/README: WHO AM I?
newaliases: cannot open /etc/mail/aliases: No such file or directory
Warning: These messages were issued while creating sendmail.cf
make sure they are benign before starting sendmail!
Errors in generating sendmail.cf
m4:/etc/mail/sendmail.mc:10: cannot open `/usr/share/sendmail-cf/m4/cf.m4': No such file or directory
Job for sendmail.service failed because the control process exited with error code. See "systemctl status sendmail.service" and "journalctl -xe" for details.
invoke-rc.d: initscript sendmail, action "start" failed.
● sendmail.service - LSB: powerful, efficient, and scalable Mail Transport Agent
Loaded: loaded (/etc/init.d/sendmail; bad; vendor preset: enabled)
Active: failed (Result: exit-code) since Sat 2018-06-09 12:32:49 EDT; 5ms ago
Docs: man:systemd-sysv-generator(8)
Process: 13910 ExecStart=/etc/init.d/sendmail start (code=exited, status=2)
Jun 09 12:32:49 yogurt sendmail[13910]: * Starting Mail Transport Agent (MTA) sendmail
Jun 09 12:32:49 yogurt sendmail[13910]: Makefile:343: warning: overriding recipe for target '/etc/aliases.db'
Jun 09 12:32:49 yogurt sendmail[13910]: Makefile:340: warning: ignoring old recipe for target '/etc/aliases.db'
Jun 09 12:32:49 yogurt sendmail[13910]: Makefile:395: warning: overriding recipe for target '/etc/aliases'
Jun 09 12:32:49 yogurt sendmail[13910]: Makefile:340: warning: ignoring old recipe for target '/etc/aliases'
Jun 09 12:32:49 yogurt sendmail[13910]: make: *** No rule to make target '/usr/share/sendmail-cf/m4/cf.m4', nee...Stop.
Jun 09 12:32:49 yogurt systemd[1]: sendmail.service: Control process exited, code=exited status=2
Jun 09 12:32:49 yogurt systemd[1]: Failed to start LSB: powerful, efficient, and scalable Mail Transport Agent.
Jun 09 12:32:49 yogurt systemd[1]: sendmail.service: Unit entered failed state.
Jun 09 12:32:49 yogurt systemd[1]: sendmail.service: Failed with result 'exit-code'.
Hint: Some lines were ellipsized, use -l to show in full.
dpkg: error processing package sendmail-bin (--configure):
subprocess installed post-installation script returned error exit status 1
Setting up procmail (3.22-25ubuntu0.16.04.1) ...
dpkg: dependency problems prevent configuration of sensible-mda:
sensible-mda depends on sendmail-bin | mail-transport-agent; however:
Package sendmail-bin is not configured yet.
Package mail-transport-agent is not installed.
Package postfix which provides mail-transport-agent is not installed.
Package sendmail-bin which provides mail-transport-agent is not configured yet.
dpkg: error processing package sensible-mda (--configure):
dependency problems - leaving unconfigured
No apport report written because the error message indicates its a followup error from a previous failure.
No apport report written because the error message indicates its a followup error from a previous failure.
dpkg: dependency problems prevent configuration of sendmail:
sendmail depends on sendmail-bin; however:
Package sendmail-bin is not configured yet.
sendmail depends on sensible-mda; however:
Package sensible-mda is not configured yet.
dpkg: error processing package sendmail (--configure):
dependency problems - leaving unconfigured
Errors were encountered while processing:
sendmail-bin
sensible-mda
sendmail
E: Sub-process /usr/bin/dpkg returned an error code (1)
# make /etc/init.d/sendmail reload
Makefile:343: warning: overriding recipe for target '/etc/aliases.db'
Makefile:340: warning: ignoring old recipe for target '/etc/aliases.db'
Makefile:395: warning: overriding recipe for target '/etc/aliases'
Makefile:340: warning: ignoring old recipe for target '/etc/aliases'
make: Nothing to be done for '/etc/init.d/sendmail'.
/etc/init.d/sendmail reload
* Reloading Mail Transport Agent (MTA) sendmail Makefile:343: warning: overriding recipe for target '/etc/aliases.db'
Makefile:340: warning: ignoring old recipe for target '/etc/aliases.db'
Makefile:395: warning: overriding recipe for target '/etc/aliases'
Makefile:340: warning: ignoring old recipe for target '/etc/aliases'
make[1]: *** No rule to make target '/usr/share/sendmail-cf/m4/cf.m4', needed by '/etc/mail/databases'. Stop.
根据教程更新后的 sendmail.mc：
# cat sendmail.mc
divert(-1)dnl
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 # /etc/mail/make
dnl #
include(`/usr/share/sendmail-cf/m4/cf.m4')dnl
VERSIONID(`setup for linux')dnl
OSTYPE(`debian')dnl
dnl #
dnl # Do not advertize sendmail version.
dnl #
dnl define(`confSMTP_LOGIN_MSG', `$j Sendmail; $b')dnl
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 #
define(`SMART_HOST', `[10.0.2.2]')dnl
dnl #
define(`confDEF_USER_ID', ``8:12'')dnl
dnl define(`confAUTO_REBUILD')dnl
define(`confTO_CONNECT', `1m')dnl
define(`confTRY_NULL_MX_LIST', `True')dnl
define(`confDONT_PROBE_INTERFACES', `True')dnl
define(`PROCMAIL_MAILER_PATH', `/usr/bin/procmail')dnl
define(`ALIAS_FILE', `/etc/aliases')dnl
define(`STATUS_FILE', `/var/log/mail/statistics')dnl
define(`UUCP_MAILER_MAX', `2000000')dnl
define(`confUSERDB_SPEC', `/etc/mail/userdb.db')dnl
define(`confPRIVACY_FLAGS', `authwarnings,novrfy,noexpn,restrictqrun')dnl
define(`confAUTH_OPTIONS', `A')dnl
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 /etc/pki/tls/certs; make sendmail.pem
dnl # Complete usage:
dnl # make -C /etc/pki/tls/certs usage
dnl #
dnl define(`confCACERT_PATH', `/etc/pki/tls/certs')dnl
dnl define(`confCACERT', `/etc/pki/tls/certs/ca-bundle.crt')dnl
dnl define(`confSERVER_CERT', `/etc/pki/tls/certs/sendmail.pem')dnl
dnl define(`confSERVER_KEY', `/etc/pki/tls/certs/sendmail.pem')dnl
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
FEATURE(`no_default_msa', `dnl')dnl
FEATURE(`smrsh')dnl
FEATURE(`mailertable', `hash -o /etc/mail/mailertable.db')dnl
FEATURE(`virtusertable', `hash -o /etc/mail/virtusertable.db')dnl
FEATURE(redirect)dnl
FEATURE(always_add_domain)dnl
FEATURE(use_cw_file)dnl
FEATURE(use_ct_file)dnl
dnl #
dnl # The following limits the number of processes sendmail can fork to accept
dnl # incoming messages or process its message queues to 20.) sendmail refuses
dnl # to accept connections once it has reached its quota of child processes.
dnl #
dnl define(`confMAX_DAEMON_CHILDREN', `20')dnl
dnl #
dnl # Limits the number of new connections per second. This caps the overhead
dnl # incurred due to forking new sendmail processes. May be useful against
dnl # DoS attacks or barrages of spam. (As mentioned below, a per-IP address
dnl # limit would be useful but is not available as an option at this writing.)
dnl #
dnl define(`confCONNECTION_RATE_THROTTLE', `3')dnl
dnl #
dnl # The -t option will retry delivery if e.g. the user runs over his quota.
dnl #
FEATURE(local_procmail, `', `procmail -t -Y -a $h -d $u')dnl
FEATURE(`access_db', `hash -T<TMPF> -o /etc/mail/access.db')dnl
FEATURE(`blacklist_recipients')dnl
EXPOSED_USER(`root')dnl
dnl #
dnl # For using Cyrus-IMAPd as POP3/IMAP server through LMTP delivery uncomment
dnl # the following 2 definitions and activate below in the MAILER section the
dnl # cyrusv2 mailer.
dnl #
dnl define(`confLOCAL_MAILER', `cyrusv2')dnl
dnl define(`CYRUSV2_MAILER_ARGS', `FILE /var/lib/imap/socket/lmtp')dnl
dnl #
dnl # The following causes sendmail to only listen on the IPv4 loopback address
dnl # 127.0.0.1 and not on any other network devices. Remove the loopback
dnl # address restriction to accept email from the internet or intranet.
dnl #
dnl # DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl
dnl #
dnl # The following causes sendmail to additionally listen to port 587 for
dnl # mail from MUAs that authenticate. Roaming users who can't reach their
dnl # preferred sendmail daemon due to port 25 being blocked or redirected find
dnl # this useful.
dnl #
dnl DAEMON_OPTIONS(`Port=submission, Name=MSA, M=Ea')dnl
dnl #
dnl # The following causes sendmail to additionally listen to port 465, but
dnl # starting immediately in TLS mode upon connecting. Port 25 or 587 followed
dnl # by STARTTLS is preferred, but roaming clients using Outlook Express can't
dnl # do STARTTLS on ports other than 25. Mozilla Mail can ONLY use STARTTLS
dnl # and doesn't support the deprecated smtps; Evolution <1.1.1 uses smtps
dnl # when SSL is enabled-- STARTTLS support is available in version 1.1.1.
dnl #
dnl # For this to work your OpenSSL certificates must be configured.
dnl #
dnl DAEMON_OPTIONS(`Port=smtps, Name=TLSMTA, M=s')dnl
dnl #
dnl # The following causes sendmail to additionally listen on the IPv6 loopback
dnl # device. Remove the loopback address restriction listen to the network.
dnl #
dnl DAEMON_OPTIONS(`port=smtp,Addr=::1, Name=MTA-v6, Family=inet6')dnl
dnl #
dnl # enable both ipv6 and ipv4 in sendmail:
dnl #
dnl DAEMON_OPTIONS(`Name=MTA-v4, Family=inet, Name=MTA-v6, Family=inet6')
dnl #
dnl # We strongly recommend not accepting unresolvable domains if you want to
dnl # protect yourself from spam. However, the laptop and users on computers
dnl # that do not have 24x7 DNS do need this.
dnl #
FEATURE(`accept_unresolvable_domains')dnl
dnl #
dnl FEATURE(`relay_based_on_MX')dnl
dnl #
dnl # Also accept email sent to "localhost.localdomain" as local email.
dnl #
LOCAL_DOMAIN(`future-access.com')dnl
dnl #
dnl # The following example makes mail from this host and any additional
dnl # specified domains appear to be sent from mydomain.com
dnl #
dnl MASQUERADE_AS(`mydomain.com')dnl
dnl #
dnl # masquerade not just the headers, but the envelope as well
dnl #
dnl FEATURE(masquerade_envelope)dnl
dnl #
dnl # masquerade not just @mydomainalias.com, but @*.mydomainalias.com as well
dnl #
dnl FEATURE(masquerade_entire_domain)dnl
dnl #
dnl MASQUERADE_DOMAIN(localhost)dnl
dnl MASQUERADE_DOMAIN(localhost.localdomain)dnl
dnl MASQUERADE_DOMAIN(mydomainalias.com)dnl
dnl MASQUERADE_DOMAIN(mydomain.lan)dnl
MAILER(smtp)dnl
MAILER(procmail)dnl
dnl MAILER(cyrusv2)dnl
divert(-1)
#
# This file is used to configure sendmail for use with Debian systems.
#
divert(0)
define(`_USE_ETC_MAIL_')dnl
include(`/usr/share/sendmail/cf/m4/cf.m4')dnl
VERSIONID(`@(#)sendmail.mc 8.9.3-21 (Debian) 20000309')
OSTYPE(`debian')dnl
DOMAIN(`debian-mta')dnl
dnl # Items controlled by /etc/mail/sendmail.conf - DO NOT TOUCH HERE
undefine(`confHOST_STATUS_DIRECTORY')dnl #DAEMON_HOSTSTATS
dnl # Items controlled by /etc/mail/sendmail.conf - DO NOT TOUCH HERE
define(`confSAFE_FILE_ENV', `/')dnl
LOCAL_CONFIG
define(`SMART_HOST', `SMTP:smtp.int.radiomaranon.org.pe')dnl
MASQUERADE_AS(radiomaranon.org.pe)dnl
FEATURE(masquerade_envelope)dnl
FEATURE(always_add_domain)dnl
Cwowie.int.radiomaranon.org.pe
CGowie.int.radiomaranon.org.pe
FEATURE(use_cw_file)dnl
FEATURE(use_ct_file)dnl
FEATURE(`nouucp', `reject')dnl
dnl define hosts we relay for
FEATURE(`access_db')dnl
dnl FEATURE(`genericstable', `hash -o /etc/mail/genericstable.db')dnl
dnl FEATURE(`virtusertable', `hash -o /etc/mail/virtusertable.db')dnl
FEATURE(accept_unresolvable_domains)
FEATURE(nocanonify)dnl
define(`confSERVICE_SWITCH_FILE',/etc/mail/service.switch)dnl
define(`confBIND_OPTS',`-AAONLY -DNSRCH -DEFNAMES')dnl
dnl see 'man resolver'
define(`confDONT_PROBE_INTERFACES', `True')dnl
define(`SMTP_MAILER_FLAGS',`e')dnl
define(`confTO_QUEUEWARN', `2d')dnl
dnl define(`confDIAL_DELAY', `0')dnl
define(`confCON_EXPENSIVE', `True')dnl
define(`confPRIVACY_FLAGS', `needmailhelo,novrfy,noexpn,noreceipts,noverb')dnl
#GMail settings:
define(`SMART_HOST',`[smtp.gmail.com]')dnl
define(`RELAY_MAILER_ARGS', `TCP $h 587')dnl
define(`ESMTP_MAILER_ARGS', `TCP $h 587')dnl
define(`confAUTH_OPTIONS', `A p')dnl
TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
FEATURE(`authinfo',`hash -o /etc/mail/authinfo/gmail.db')dnl
MAILER_DEFINITIONS
MAILER(local)dnl
MAILER(smtp)dnl
MAILER(procmail)dnl
验证信息：
# echo $PWD
/etc/mail/authinfo
# cat authinfo
AuthInfo: U:root I:[email protected] P:mypwd
# cat gmail
AuthInfo: "U:root" "I:[email protected]" "P:mypwd"
答案1
虽然我仍然认为你应该使用mailx而不是成熟的 MTA 通过 gmail 发送电子邮件（https://www.systutorials.com/1411/sending-email-from-mailx-command-in-linux-using-gmails-smtp/）我将为您提供使用sendmail+gmail 配置的示例。
首先，您需要 sasl，libplain因为 SMTP 身份验证基于 SASL，而 Sendmail 使用 Cyrus SASL（https://www.cyrusimap.org/sasl/）来实现身份验证。请确保安装它，否则您将遇到“AUTH=客户端，可用机制不能满足要求“在您的 中maillog。您还需要，openssl因为 sendmail 使用它进行 TLS，但它应该已经安装好了。
CentOS/RH：yum install cyrus-sasl-plain openssl
乌本图：apt-get install libsasl2-modules openssl
因此，这是我的mc文件和评论。
divert(-1)dnl
include(`/usr/share/sendmail-cf/m4/cf.m4')dnl centos's specific path, you may have different
VERSIONID(`setup for linux')dnl
OSTYPE(`linux')dnl
define(`confDEF_USER_ID', ``8:12'')dnl
define(`ALIAS_FILE', `/etc/aliases')dnl
define(`confPRIVACY_FLAGS', `authwarnings,novrfy,noexpn,restrictqrun')dnl just to force clients obey SMTP
define(`confAUTH_MECHANISMS', `PLAIN')dnl Gmail is OK with SASL-PLAIN when used with TLS
FEATURE(authinfo)dnl This feature enables /etc/mail/authinfo
define(`SMART_HOST', `smtp.gmail.com')dnl Always send email to this host instead of MX
define(`confTO_IDENT', `0')dnl disable prehistoric IDENT proto
FEATURE(`no_default_msa', `dnl')dnl MSA (567 port) is good idea, but nobody uses it
FEATURE(nouucp, `nospecial')dnl Nobody needs UUCP these days
FEATURE(nocanonify)dnl We assume that client always provides DQDN
EXPOSED_USER(`root')dnl
DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl Listen localhost:25
MAILER(smtp)dnl The only mailer I need is SMTP, I do not use local mail
这里是/etc/mail/authinfo（确保[MY_LOGIN_ON_GMAIL]用您的实际登录名替换）
AuthInfo: "I:[MY_LOGIN_ON_GMAIL]@gmail.com" "P:[MY_PASSWORD_ON_GMAIL]"
它的含义：“始终对任何 SMTP 连接使用 AuthInfo，使用 [MY_LOGIN_ON_GMAIL]@gmail.com 作为登录名，使用 [MY_PASSWORD_ON_GMAIL]”作为密码。
您可能需要将此文件编译为哈希数据库（在许多操作系统上，您可能会make在其中调用/etc/mail）并将.mc文件转换为sendmail.cf（命令是特定于操作系统的，make可能会有效）并重新启动 sendmail（make restart在/etc/mail或“systemctl restart sendmail”）
咱们试试吧：echo "Hello" | mail -r [MY_LOGIN_ON_GMAIL]@gmail.com -s "Hey, it works" [MY_LOGIN_ON_GMAIL]@gmail.com
-r这里是“来自”。
就这些。
如果有任何问题，请检查/var/log/mail
PS：要检查authinfosendmail 是否使用了规则集（这意味着您对mc文件的更改在文件中cf），请使用
echo "authinfo test test" | sendmail -bt。您应该会看到您的登录名/密码