我正在尝试配置 POSTFIX 通过以下方式发送电子邮件smtp.gmail.com，但没有任何成功。我尝试过以下两个教程：
https://www.endpoint.com/blog/2019/04/30/postfix-gmail-forwarder
https://www.linode.com/docs/guides/configure-postfix-to-send-mail-using-gmail-and-google-apps-on-debian-or-ubuntu/
这些教程都没用，不管我怎么做，我都会在日志中收到退回的消息。此外，当我通过 sendmail 发送电子邮件时，我的发件人地址似乎被“root@observium-pi“。
还:我知道理论上它是可行的，因为我有一个 OpenHAB smtp 连接器，可以使用相同的 SMTP 成功发送电子邮件。
这是我的主配置文件：
# See /usr/share/postfix/main.cf.dist for a commented, more complete version
# Debian specific: Specifying a file name will cause the first
# line of that file to be used as the name. The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname
smtpd_banner = $myhostname ESMTP $mail_name (Raspbian)
biff = no
# appending .domain is the MUA's job.
append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = no
# See http://www.postfix.org/COMPATIBILITY_README.html -- default to 2 on
# fresh installs.
compatibility_level = 2
# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
#smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = observium-pi
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination = $myhostname, observium-pi, localhost.localdomain, localhost
relayhost = [smtp.gmail.com]:465
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = loopback-only
default_transport = error
relay_transport = error
inet_protocols = all
smtp_tls_wrappermode = yes
smtp_tls_security_level = verify
smtp_tls_mandatory_protocols = !SSLv2, !TLSv1, !TLSv1.1
tls_high_cipherlist = ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256
smtp_tls_mandatory_ciphers = high
smtp_tls_loglevel = 2
smtp_sasl_auth_enable = yes
smtp_sasl_mechanism_filter = plain
smtp_sasl_password_maps = hash:/etc/postfix/smtp_auth
smtp_sasl_security_options = noanonymous
header_checks = regexp:/etc/postfix/header_checks
You have new mail in /var/mail/root
这是我的smtp_身份验证（模糊处理），我正在使用应用程序特定密码：
[smtp.gmail.com]:465 s******[email protected]:****************
以下是日志：
Jan 20 17:53:48 observium-pi postfix/pickup[13165]: 49AC73F2D5: uid=0 from=<root@observium-pi>
Jan 20 17:53:48 observium-pi postfix/cleanup[13725]: 49AC73F2D5: message-id=<20210120155348.49AC73F2D5@observium-pi>
Jan 20 17:53:48 observium-pi postfix/qmgr[13166]: 49AC73F2D5: from=<root@observium-pi>, size=354, nrcpt=1 (queue active)
Jan 20 17:53:48 observium-pi postfix/error[13727]: 49AC73F2D5: to=<s******[email protected]>, relay=none, delay=0.23, delays=0.13/0.04/0/0.06, dsn=5.0.0, status=bounced ([smtp.gmail.com]:465)
Jan 20 17:53:48 observium-pi postfix/cleanup[13725]: 728643F2D6: message-id=<20210120155348.728643F2D6@observium-pi>
Jan 20 17:53:48 observium-pi postfix/qmgr[13166]: 728643F2D6: from=<>, size=2169, nrcpt=1 (queue active)
Jan 20 17:53:48 observium-pi postfix/bounce[13728]: 49AC73F2D5: sender non-delivery notification: 728643F2D6
Jan 20 17:53:48 observium-pi postfix/qmgr[13166]: 49AC73F2D5: removed
Jan 20 17:53:49 observium-pi postfix/local[13729]: 728643F2D6: to=<root@observium-pi>, relay=local, delay=0.95, delays=0.02/0.05/0/0.88, dsn=2.0.0, status=sent (delivered to mailbox)
Jan 20 17:53:49 observium-pi postfix/qmgr[13166]: 728643F2D6: removed
编辑：
Contents of the bounce email:
From MAILER-DAEMON Wed Jan 20 17:51:19 2021
Return-Path: <>
X-Original-To: root@observium-pi
Delivered-To: root@observium-pi
Received: by observium-pi (Postfix)
id ECBA13F2D6; Wed, 20 Jan 2021 17:51:18 +0200 (IST)
Date: Wed, 20 Jan 2021 17:51:18 +0200 (IST)
From: MAILER-DAEMON@observium-pi (Mail Delivery System)
Subject: Undelivered Mail Returned to Sender
To: root@observium-pi
Auto-Submitted: auto-replied
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
boundary="2FE3A3F2D5.1611157878/observium-pi"
Content-Transfer-Encoding: 8bit
Message-Id: <20210120155118.ECBA13F2D6@observium-pi>
Status: O
X-UID: 17
This is a MIME-encapsulated message.
--2FE3A3F2D5.1611157878/observium-pi
Content-Description: Notification
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
This is the mail system at host observium-pi.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
<shaul@s******v.com>: [smtp.gmail.com]:465
--2FE3A3F2D5.1611157878/observium-pi
Content-Description: Delivery report
Content-Type: message/delivery-status
Reporting-MTA: dns; observium-pi
X-Postfix-Queue-ID: 2FE3A3F2D5
X-Postfix-Sender: rfc822; root@observium-pi
Arrival-Date: Wed, 20 Jan 2021 17:50:47 +0200 (IST)
Final-Recipient: rfc822; shaul@s******v.com
Original-Recipient: rfc822;shaul@s******v.com
Action: failed
Status: 5.0.0
Diagnostic-Code: X-Postfix; [smtp.gmail.com]:465
--2FE3A3F2D5.1611157878/observium-pi
Content-Description: Undelivered Message
Content-Type: message/rfc822
Content-Transfer-Encoding: 8bit
Return-Path: <root@observium-pi>
Received: by observium-pi (Postfix, from userid 0)
id 2FE3A3F2D5; Wed, 20 Jan 2021 17:51:16 +0200 (IST)
from: s******[email protected]
subject: quick email
Message-Id: <20210120155117.2FE3A3F2D5@observium-pi>
Date: Wed, 20 Jan 2021 17:50:47 +0200 (IST)
sending a quick email
--2FE3A3F2D5.1611157878/observium-pi--