From: Sandy Cash Jr <lhcash(a)us.ibm.com>
Reply: Discussions about Cloud Foundry projects and the system overall. <cf-dev(a)lists.cloudfoundry.org>>
Date: June 18, 2015 at 15:00:50
To: cf-dev(a)lists.cloudfoundry.org <cf-dev(a)lists.cloudfoundry.org>>
Subject:  Re: [cf-dev] cf-dev Digest, Vol 3, Issue 92

Since sendmail appears to be missing from the CF stemcell, how are
people sending email from PHP apps?

Thanks,
matt

I am not a PHP guy at all, and I don't know if this is part of the PHP buildback, but PEAR::mail (http://pear.php.net/package/Mail) appears to support remote STMP hosts, which would obviate the need for a local sendmail binary.
I’m also not a PHP developer, however your suggestion is in line with cloud-native application development. That is to say, “treat backing services as attached resources”.

Typically when requiring a backing service, such as outbound email, you use a third-party service. This could be a direct SMTP interaction to, say, gmail, or it could be via an API such as SendGrid. I’m not advocating a particular service, that requires research into your app’s needs, but the general approach is advised.

— Casey