问EXIM允许通过telnet向任何域发送邮件，而无需登录/身份验证。

EN

root@vps:~# telnet example.com 25
Trying 19x.10x.8x.1xx...
Connected to example.com.
Escape character is '^]'.
220 serwer.example.com.pl ESMTP Exim 4.91 Wed, 19 Sep 2018 10:48:05 
+0200
mail from: xyz@example.com
250 OK
rcpt to: outerbox@gmail.com
250 Accepted
data
354 Enter message, ending with "." on a line by itself
test data.
.
250 OK id=1g2Y9t-0003yu-Of

addresslist whitelist_senders = lsearch;/etc/virtual/whitelist_senders
addresslist blacklist_senders = lsearch;/etc/virtual/blacklist_senders
domainlist blacklist_domains = lsearch;/etc/virtual/blacklist_domains
domainlist whitelist_domains = lsearch;/etc/virtual/whitelist_domains
domainlist local_domains = lsearch;/etc/virtual/domains
domainlist relay_domains = 
domainlist use_rbl_domains = lsearch;/etc/virtual/use_rbl_domains
hostlist auth_relay_hosts = 
hostlist bad_sender_hosts = lsearch;/etc/virtual/bad_sender_hosts
hostlist bad_sender_hosts_ip = net-lsearch;/etc/virtual/bad_sender_hosts
hostlist relay_hosts = 
hostlist whitelist_hosts = lsearch;/etc/virtual/whitelist_hosts
hostlist whitelist_hosts_ip = net-lsearch;/etc/virtual/whitelist_hosts

begin authenticators

plain:
    driver = plaintext
    public_name = PLAIN
    server_prompts = :
    server_condition = "${perl{smtpauth}}"
    server_set_id = $2

login:
    driver = plaintext
    public_name = LOGIN
    server_prompts = "Username:: : Password::"
    server_condition = "${perl{smtpauth}}"
    server_set_id = $1