No Sendmail but ISPConfig Postfix

Question

This is what php uses to send php mail with the php mail() function:

; For Unix only.  You may supply arguments as well (default: "sendmail -t -i").                                                                                                                                   
; http://www.php.net/manual/en/mail.configuration.php#ini.sendmail-path 


sendmail_path = /usr/sbin/sendmail -t -i  //sendmail command to send mail

but its not sending the mail to the recipient and I get this in the maillog:

Dec  1 12:52:09 srvload1 postfix/qmgr[25215]: D3982162BB6: from=<sxxxx@xxxxxxxxx.com>, size=524, nrcpt=1 (queue active)
Dec  1 12:52:09 srvload1 postfix/qmgr[25215]: warning: connect to transport private/[127.0.0.1]: No such file or directory
Dec  1 12:52:09 srvload1 postfix/error[25563]: D3982162BB6: to=<sxxxx@xxxxxxxxx.com>, relay=none, delay=0.03, delays=0.03/0/0/0, dsn=4.3.0, status=deferred (mail transport unavailable)

warning: connect to transport private/[127.0.0.1]: ? and it gets queued. It doesn't send.

my server admin told me we don't have sendmail installed and I don't want to have it install it on the server, it may disrupt our service.

is there a way to send php mail() without sendmail? The server runs ISPConfig CentOS Postfix and I think Procmail

[root@srvload1 ~]# which procmail
/usr/bin/procmail

[root@srvload1 ~]# cat /etc/issue
CentOS release 6.5 (Final)
Kernel \r on an \m

Answer 1

There seems to be a number of false assumptions here but the short and pointed answer is that your Postfix configuration is hosed and needs to be corrected.

With the information you provide, I can't tell you how. Perhaps update your question to include pertinent snippets from your Postfix config (or maybe post a new, better focused question, and delete this one). Basically we'd need to see anything non-standard from your /etc/postfix/master.cf and especially anything involving the private/[127.0.0.1] transport. Other transport configurations could be useful for context as well.

You don't need to install Sendmail but you do need to have a working configuration for outgoing mail.

/usr/sbin/sendmail is actually a Postfix compatibility wrapper which implements the basic Sendmail functionality. For legacy reasons, sendmail is the canonical name for this, even though Sendmail the MTA is no longer the dominant or standard MTA.

Procmail is unrelated to outgoing mail (unless you have a very customized config, in which case you should document it).