我的邮件服务器（Postfix+Dovecot）有问题，它可以接收邮件，但遗憾的是无法发送邮件！
供参考，该服务器在 Debian 9 上运行并由 OVH 托管。
以下是我尝试发送邮件时（使用 Thunderbird 从客户端发送）发生的 /var/log/mail.log 条目：
1 -- postfix/submission/smtpd[984]: input attribute value: 1
2 -- postfix/submission/smtpd[984]: private/tlsmgr: wanted attribute: timeout
3 -- postfix/submission/smtpd[984]: input attribute name: timeout
4 -- postfix/submission/smtpd[984]: input attribute value: 3600
5 -- postfix/submission/smtpd[984]: private/tlsmgr: wanted attribute: (list terminator)
6 -- postfix/submission/smtpd[984]: input attribute name: (end)
7 -- postfix/submission/smtpd[984]: match_string: parent_domain_matches_subdomains: fast_flush_domains ~? debug_peer_list
8 -- postfix/submission/smtpd[984]: match_string: parent_domain_matches_subdomains: fast_flush_domains ~? fast_flush_domains
9 -- postfix/submission/smtpd[984]: auto_clnt_create: transport=local endpoint=private/anvil
10 -- postfix/submission/smtpd[984]: connection established
11 -- postfix/submission/smtpd[984]: master_notify: status 0
12 -- postfix/submission/smtpd[984]: name_mask: resource
13 -- postfix/submission/smtpd[984]: name_mask: software
14 -- postfix/submission/smtpd[984]: connect from [CLIENTNAME][[CLIENTIP]]
15 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTNAME]: no match
16 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTIP]: no match
17 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTNAME]: no match
18 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTIP]: no match
19 -- postfix/submission/smtpd[984]: match_hostname: debug_peer_list: [CLIENTNAME] ~? 127.0.0.1
20 -- postfix/submission/smtpd[984]: match_hostaddr: debug_peer_list: [CLIENTIP] ~? 127.0.0.1
21 -- postfix/submission/smtpd[984]: match_hostname: debug_peer_list: [CLIENTNAME] ~? [MYDOMAIN]
22 -- postfix/submission/smtpd[984]: match_hostaddr: debug_peer_list: [CLIENTIP] ~? [MYDOMAIN]
23 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTNAME]: no match
24 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTIP]: no match
25 -- postfix/submission/smtpd[984]: smtp_stream_setup: maxtime=300 enable_deadline=0
26 -- postfix/submission/smtpd[984]: match_hostname: smtpd_client_event_limit_exceptions: [CLIENTNAME] ~? 127.0.0.0/8
27 -- postfix/submission/smtpd[984]: match_hostaddr: smtpd_client_event_limit_exceptions: [CLIENTIP] ~? 127.0.0.0/8
28 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTNAME]: no match
29 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTIP]: no match
30 -- postfix/submission/smtpd[984]: auto_clnt_open: connected to private/anvil
31 -- postfix/submission/smtpd[984]: send attr request = connect
32 -- postfix/submission/smtpd[984]: send attr ident = submission:[CLIENTIP]
33 -- postfix/submission/smtpd[984]: private/anvil: wanted attribute: status
34 -- postfix/submission/smtpd[984]: input attribute name: status
35 -- postfix/submission/smtpd[984]: input attribute value: 0
36 -- postfix/submission/smtpd[984]: private/anvil: wanted attribute: count
37 -- postfix/submission/smtpd[984]: input attribute name: count
38 -- postfix/submission/smtpd[984]: input attribute value: 1
39 -- postfix/submission/smtpd[984]: private/anvil: wanted attribute: rate
40 -- postfix/submission/smtpd[984]: input attribute name: rate
41 -- postfix/submission/smtpd[984]: input attribute value: 1
42 -- postfix/submission/smtpd[984]: private/anvil: wanted attribute: (list terminator)
43 -- postfix/submission/smtpd[984]: input attribute name: (end)
44 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 220 teshar.[MYDOMAIN] ESMTP Postfix (Debian/GNU)
45 -- postfix/submission/smtpd[984]: < [CLIENTNAME][[CLIENTIP]]: EHLO [192.168.0.10]
46 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTNAME]: no match
47 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTIP]: no match
48 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-[MYHOSTDOMAIN]
49 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-PIPELINING
50 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-SIZE 10240000
51 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-VRFY
52 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-ETRN
53 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-STARTTLS
54 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-ENHANCEDSTATUSCODES
55 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-8BITMIME
56 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-DSN
57 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250 SMTPUTF8
58 -- postfix/submission/smtpd[984]: < [CLIENTNAME][[CLIENTIP]]: STARTTLS
59 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 220 2.0.0 Ready to start TLS
60 -- postfix/submission/smtpd[984]: setting up TLS connection from [CLIENTNAME][[CLIENTIP]]
61 -- postfix/submission/smtpd[984]: [CLIENTNAME][[CLIENTIP]]: TLS cipher list "aNULL:-aNULL:HIGH:MEDIUM:+RC4:@STRENGTH:!MD5:!DES:!ADH:!RC4:!PSD:!SRP:!3DES:!eNULL:!aNULL:!MD5:!DES:!ADH:!RC4:!PSD:!SRP:!3DES:!eNULL:!aNULL"
62 -- postfix/submission/smtpd[984]: send attr request = seed
63 -- postfix/submission/smtpd[984]: send attr size = 32
64 -- postfix/submission/smtpd[984]: private/tlsmgr: wanted attribute: status
65 -- postfix/submission/smtpd[984]: input attribute name: status
66 -- postfix/submission/smtpd[984]: input attribute value: 0
67 -- postfix/submission/smtpd[984]: private/tlsmgr: wanted attribute: seed
68 -- postfix/submission/smtpd[984]: input attribute name: seed
69 -- postfix/submission/smtpd[984]: input attribute value: KOIm2ud2wCvuYcE8nKhw1RrGwmpKX0gw7kT4sLbysT4=
70 -- postfix/submission/smtpd[984]: private/tlsmgr: wanted attribute: (list terminator)
71 -- postfix/submission/smtpd[984]: input attribute name: (end)
72 -- postfix/submission/smtpd[984]: SSL_accept:before SSL initialization
73 -- postfix/submission/smtpd[984]: SSL_accept:before SSL initialization
74 -- postfix/submission/smtpd[984]: send attr request = tktkey
75 -- postfix/submission/smtpd[984]: send attr keyname = [data 16 bytes]
76 -- postfix/submission/smtpd[984]: private/tlsmgr: wanted attribute: status
77 -- postfix/submission/smtpd[984]: input attribute name: status
78 -- postfix/submission/smtpd[984]: input attribute value: 4294967295
79 -- postfix/submission/smtpd[984]: private/tlsmgr: wanted attribute: keybuf
80 -- postfix/submission/smtpd[984]: input attribute name: keybuf
81 -- postfix/submission/smtpd[984]: input attribute value: 9oQDVRdjTvMeJ/jn0uOC3g==
82 -- postfix/submission/smtpd[984]: private/tlsmgr: wanted attribute: (list terminator)
83 -- postfix/submission/smtpd[984]: input attribute name: (end)
84 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS read client hello
85 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS write server hello
86 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS write certificate
87 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS write key exchange
88 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS write server done
89 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS write server done
90 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS read client key exchange
91 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS read change cipher spec
92 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS read finished
93 -- postfix/submission/smtpd[984]: send attr request = tktkey
94 -- postfix/submission/smtpd[984]: send attr keyname = [data 0 bytes]
95 -- postfix/submission/smtpd[984]: private/tlsmgr: wanted attribute: status
96 -- postfix/submission/smtpd[984]: input attribute name: status
97 -- postfix/submission/smtpd[984]: input attribute value: 0
98 -- postfix/submission/smtpd[984]: private/tlsmgr: wanted attribute: keybuf
99 -- postfix/submission/smtpd[984]: input attribute name: keybuf
100 -- postfix/submission/smtpd[984]: input attribute value: GS4aMvZYYdXW1YceMhQci3PUTQMO/Y/DqBWSZmv8PmTQ8yVeCJL5ZN4VqHMk0jVglcG5vVfLUGluXxMUkDkHrvMcOWwBBjemd8eZhpQzfdP5iBddAAAAAA==
101 -- postfix/submission/smtpd[984]: private/tlsmgr: wanted attribute: (list terminator)
102 -- postfix/submission/smtpd[984]: input attribute name: (end)
103 -- postfix/submission/smtpd[984]: [CLIENTNAME][[CLIENTIP]]: Issuing session ticket, key expiration: 1561823481
104 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS write session ticket
105 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS write change cipher spec
106 -- postfix/submission/smtpd[984]: SSL_accept:SSLv3/TLS write finished
107 -- postfix/submission/smtpd[984]: Anonymous TLS connection established from [CLIENTNAME][[CLIENTIP]]: TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)
108 -- postfix/submission/smtpd[984]: xsasl_dovecot_server_create: SASL service=smtp, realm=(null)
109 -- postfix/submission/smtpd[984]: name_mask: noanonymous
110 -- postfix/submission/smtpd[984]: xsasl_dovecot_server_connect: Connecting
111 -- postfix/submission/smtpd[984]: xsasl_dovecot_server_connect: auth reply: VERSION?1?1
112 -- postfix/submission/smtpd[984]: xsasl_dovecot_server_connect: auth reply: MECH?LOGIN?plaintext
113 -- postfix/submission/smtpd[984]: name_mask: plaintext
114 -- postfix/submission/smtpd[984]: xsasl_dovecot_server_connect: auth reply: SPID?989
115 -- postfix/submission/smtpd[984]: xsasl_dovecot_server_connect: auth reply: CUID?1
116 -- postfix/submission/smtpd[984]: xsasl_dovecot_server_connect: auth reply: COOKIE?f9b6043b1239b511c8d485c337183bad
117 -- postfix/submission/smtpd[984]: xsasl_dovecot_server_connect: auth reply: DONE
118 -- postfix/submission/smtpd[984]: xsasl_dovecot_server_mech_filter: keep mechanism: LOGIN
119 -- postfix/submission/smtpd[984]: < [CLIENTNAME][[CLIENTIP]]: EHLO [192.168.0.10]
120 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTNAME]: no match
121 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTIP]: no match
122 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-[MYHOSTDOMAIN]
123 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-PIPELINING
124 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-SIZE 10240000
125 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-VRFY
126 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-ETRN
127 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-AUTH LOGIN
128 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-AUTH=LOGIN
129 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-ENHANCEDSTATUSCODES
130 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-8BITMIME
131 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250-DSN
132 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 250 SMTPUTF8
133 -- postfix/submission/smtpd[984]: < [CLIENTNAME][[CLIENTIP]]: QUIT
134 -- postfix/submission/smtpd[984]: > [CLIENTNAME][[CLIENTIP]]: 221 2.0.0 Bye
135 -- postfix/submission/smtpd[984]: match_hostname: smtpd_client_event_limit_exceptions: [CLIENTNAME] ~? 127.0.0.0/8
136 -- postfix/submission/smtpd[984]: match_hostaddr: smtpd_client_event_limit_exceptions: [CLIENTIP] ~? 127.0.0.0/8
137 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTNAME]: no match
138 -- postfix/submission/smtpd[984]: match_list_match: [CLIENTIP]: no match
139 -- postfix/submission/smtpd[984]: send attr request = disconnect
140 -- postfix/submission/smtpd[984]: send attr ident = submission:[CLIENTIP]
141 -- postfix/submission/smtpd[984]: private/anvil: wanted attribute: status
142 -- postfix/submission/smtpd[984]: input attribute name: status
143 -- postfix/submission/smtpd[984]: input attribute value: 0
144 -- postfix/submission/smtpd[984]: private/anvil: wanted attribute: (list terminator)
145 -- postfix/submission/smtpd[984]: input attribute name: (end)
146 -- postfix/submission/smtpd[984]: disconnect from [CLIENTNAME][[CLIENTIP]] ehlo=2 starttls=1 quit=1 commands=4
147 -- postfix/submission/smtpd[984]: master_notify: status 1
148 -- postfix/submission/smtpd[984]: connection closed
149 -- postfix/submission/smtpd[984]: proxymap stream disconnect
150 -- postfix/submission/smtpd[984]: auto_clnt_close: disconnect private/tlsmgr stream
因此，客户端似乎请求 STARTTLS 传输（第 122 行）。这会导致 TLS 握手（-> 第 106 行）和身份验证（-> 第 118 行）。然后，连接似乎重新启动（第 122 行），最终由客户端发出“QUIT”（l133）。
/var/log/mail.err、systemctl status postfix、systemctl status dovecot 中没有条目。
我从我的邮件客户端（thunderbird）收到以下错误消息：“发送消息失败”。
我认为我的 AUTH 过程出了问题，但需要您的帮助来澄清这一点。
以下是“postconf -n”的输出
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
biff = no
broken_sasl_auth_clients = yes
compatibility_level = 2
debug_peer_level = 10
debug_peer_list = 127.0.0.1, $mydomain
home_mailbox = Maildir/
inet_interfaces = all
inet_protocols = ipv4
mailbox_size_limit = 0
mydestination = $myhostname, $mydomain, localhost.$mydomain, localhost
myhostname = [HIDDEN]
mynetworks = 127.0.0.0/8
myorigin = /etc/mailname
readme_directory = no
recipient_delimiter = +
relayhost =
smtp_tls_cert_file = /etc/letsencrypt/live/[MYDOMAIN]/fullchain.pem
smtp_tls_ciphers = medium
smtp_tls_exclude_ciphers = MD5, DES ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL
smtp_tls_key_file = /etc/letsencrypt/live/[MYDOMAIN]/privkey.pem
smtp_tls_mandatory_ciphers = medium
smtp_tls_mandatory_exclude_ciphers = MD5, DES ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL
smtp_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1
smtp_tls_note_starttls_offer = yes
smtp_tls_protocols = !SSLv2,!SSLv3,!TLSv1
smtp_tls_security_level = may
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtp_use_tls = yes
smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
smtpd_helo_required = yes
smtpd_helo_restrictions = permit_mynetworks, permit_sasl_authenticated
smtpd_sasl_auth_enable = yes
smtpd_sasl_path = private/auth
smtpd_sasl_security_options = noanonymous
smtpd_sasl_type = dovecot
smtpd_tls_auth_only = yes
smtpd_tls_cert_file = /etc/letsencrypt/live/[MYDOMAIN]/fullchain.pem
smtpd_tls_ciphers = medium
smtpd_tls_exclude_ciphers = MD5, DES ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL
smtpd_tls_key_file = /etc/letsencrypt/live/[MYDOMAIN]/privkey.pem
smtpd_tls_loglevel = 3
smtpd_tls_mandatory_ciphers = medium
smtpd_tls_mandatory_exclude_ciphers = MD5, DES ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL
smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1
smtpd_tls_protocols = !SSLv2,!SSLv3, !TLSv1
smtpd_tls_received_header = yes
smtpd_tls_security_level = may
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtpd_use_tls = yes
tls_preempt_cipherlist = yes
以下是“postconf -Mf”的输出
smtp inet n - n - - smtpd -v
submission inet n - n - - smtpd -v
-o syslog_name=postfix/submission
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_reject_unlisted_recipient=no
smtps inet n - n - - smtpd -v
pickup unix n - n 60 1 pickup
cleanup unix n - n - 0 cleanup
qmgr unix n - n 300 1 qmgr
tlsmgr unix - - n 1000? 1 tlsmgr
rewrite unix - - n - - trivial-rewrite
bounce unix - - n - 0 bounce
defer unix - - n - 0 bounce
trace unix - - n - 0 bounce
verify unix - - n - 1 verify
flush unix n - n 1000? 0 flush
proxymap unix - - n - - proxymap
proxywrite unix - - n - 1 proxymap
smtp unix - - n - - smtp
relay unix - - n - - smtp
showq unix n - n - - showq
error unix - - n - - error
retry unix - - n - - error
discard unix - - n - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - n - - lmtp
anvil unix - - n - 1 anvil
scache unix - - n - 1 scache flags=DRhu
user=vmail argv=/usr/bin/maildrop -d ${recipient}
感谢您的时间和考虑:)
编辑：删除了 /var/log/mail.log 中的时间 + 主机名条目
答案1
您的配置与邮件客户端的常见配置和预期配置不同：您在所有 smtpd 端口上提供 STARTTLS。您的邮件客户端直接退出（我怀疑是因为它没有针对此设置进行配置）。
通常，您会在端口 465 上提供干净的 TLS - 同时期望客户端首先在端口 25 和 587 上说。STARTTLS任何现代邮件客户端都会自动获得正确的设置，因为启动安全连接的两种方法都可以使用默认设置。
更改您的master.cf以告诉 postfix 在您的日志中突出显示非 STARTTLS 启动的会话，并在端口 465 上提供直接 TLS 启动，类似于您对端口 587 所做的操作：
smtps inet n - n - - smtpd -v
-o syslog_name=postfix/smtps
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
-o smtpd_reject_unlisted_recipient=no
然后，删除你的不安全 smtpd_sasl_auth_enable并smtpd_sasl_security_options在您的 main.cf 中 - 因为您可能不想允许邮件客户端在端口 25 上传递经过身份验证的邮件，而只允许在为此目的明确启用的两个提交端口上传递经过身份验证的邮件。
当一切正常时，您可能还希望删除-v和inet_protocols标志，我猜它们是测试后剩下的。
答案2
感谢本教程，通过允许在服务器端传输加密密码，部分问题得到解决达夫科特 维基。