Php – apache , php , sendmail not working

You have a bad installation somehow.

It is conventional on Unix that a program exists in /usr/sbin/sendmail$, which acts as an interface to the local MTA. This MTA is rarely sendmail nowadays, but other MTA's have a compatible program which is installed here.

sendmail.h would be part of the source code for sendmail, and sendmail.0 and sendmail.8 would be the man pages, so it looks like you've somehow got the source code for the right sendmail in /usr/sbin

You need to clean this up, and get a proper sendmail program into /usr/sbin/sendmail to fix php. Since you've not told us the distribution, nor which MTA you're actually using, no-one else can help you.

$ = Actually one or more of /usr/lib/sendmail and /usr/bin/sendmail as well as /usr/sbin/sendmail, programs will either search these paths, or have one or more hardcoded into them, or ask at installation time. It looks like your program is using /usr/sbin/sendmail. Regardless of which, the installation for the MTA will do it.

In the routers section of your exim config, you'll have a router that looks something like this:

 lookuphost:
    driver = lookuphost
    transport = remote_smtp

This is what tells exim to deliver mail directly. You need to tell it to use the smarthost instead.

Replace the above router with something like this:

 smarthost:
   driver = manualroute
   domains= ! +local_domains
   transport = remote_smtp 
   route_list = *  smtp.ultrahosting.com  byname
   host_find_failed = defer
   no_more

Make sure that the transport name in the new router is the same as in the original (remote_smtp in this example).

Also, you'll need to restart exim after making these changes.