mail server – postfix: continue to add the domain name to the sender

I have two servers with the same configuration. The first sends mails well, the other will not send mail. It seems that the problem is the sender. When I send a local mail using:

echo & # 39; Message & # 39; | mailx -s & # 39; Test & # 39; info@domain.com

in the postfix journal, it will read:

de =

on the first server, it reads correctly:

de =

I checked / etc / hostname, / etc / hosts, checked the correct mydomain and myhostname with postconfig. The exit of postconf -n is exactly the same thing:

alias_database = hash: / etc / aliases
alias_maps = hash: / etc / aliases
order_directory = / usr / sbin
config_directory = / etc / postfix
daemon_directory = / usr / libexec / postfix
data_directory = / var / lib / postfix
debug_peer_level = 2
debugger_command = PATH = / bin: / usr / bin: / usr / local / bin: / usr / X11R6 / bin ddd $ demon_directory / $ process_name $ id_process & sleep 5
html_directory = no
inet_interfaces = localhost
inet_protocols = all
mail_owner = postfix
mailq_path = /usr/bin/mailq.postfix
manpage_directory = / usr / share / man
mydestination = $ myhostname, localhost. $ mydomain, localhost
newaliases_path = /usr/bin/newaliases.postfix
directory_file = / var / spool / postfix
readme_directory = /usr/share/doc/postfix-2.10.1/README_FILES
relayhost = [host.relay.com]: 587
sample_directory = /usr/share/doc/postfix-2.10.1/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash: / etc / postfix / sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_tls_CAfile = /etc/ssl/certs/ca-bundle.crt
smtp_use_tls = yes
unknown_local_recipient_reject_code = 550

the mail.cf is set to all default values, except for the addition of relayhost and SASL function.

I tried to put the mydomain and my host explicitly in main.cf but that seems to be ignored, just like putting root: root@subdomain.domain.com in / etc / aliases and then do newaliases and restarting postfix does not change anything.

I've also tried sending an email with a PHP script, no difference.

the main.cf On Server 1, just like on Server 2, they both use the same system (CentOS 7) and the same software. The only difference is that they are on different domains (for example, subdomain.domain1.com and subdomain.domain2.com). This could be a possibility, but it seems self-evident.

However, the server 1 can send a mail perfectly mailx above, as well as the aforementioned PHP script (which is nothing more than a simple mail() order.

What could cause Postfix to seemingly ignore the domain / host settings, while taking into account the correct values ​​but insisting on adding the domain to the sender's address?