After deploy centos and installing postfix I've notoced a warning at /var/log/maillog when postfix statrs:

postfix/postfix-script: warning: /usr/lib/sendmail and /usr/sbin/sendmail differ
postfix/postfix-script: warning: Replace one by a symbolic link to the other

I checked all links:

1) /usr/lib/sendmail -> /etc/alternatives/mta-sendmail > /usr/lib/sendmail.postfix -> ../sbin/sendmail.postfix
2) /usr/sbin/sendmail -> /etc/alternatives/mta -> /usr/sbin/sendmail.postfix

* Both links leading to the same file

Could someone help me to figure out with it what and where exactly it's "differ" and how it should be!?

Thanks in advance!

If you haven't installed:

system-switch-mail

Try installing that with yum. Then execute it and it should clear up any problems with scripts.

Thanks just fixed that...

# postfix check
/etc/postfix/postfix-script: line 254: cmp: command not found
postfix/postfix-script: warning: /usr/lib/sendmail and /usr/sbin/sendmail differ
postfix/postfix-script: warning: Replace one by a symbolic link to the other

Problem in missed "cmp" command to compare files and postfix mess with it. For all who use centos please "yum install diffutils" before/after you install postfix!