<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
John,<br>
<br>
tl;dr: It's using your system-level CA stores.<br>
<br>
PHPMailer uses the openssl library. In CentOS, php relies on the
operating system default locations for finding openssl's certificate
store.<br>
<br>
The answers appear to be here:<br>
<a class="moz-txt-link-freetext" href="https://stackoverflow.com/questions/37043442/how-to-add-certificate-authority-file-in-centos-7">https://stackoverflow.com/questions/37043442/how-to-add-certificate-authority-file-in-centos-7</a><br>
<br>
Cheers,<br>
Jules.<br>
<br>
<div class="moz-cite-prefix">On 21/04/2020 23:45, John Thurston via
ZendTo wrote:<br>
</div>
<blockquote type="cite"
cite="mid:WM!d45712d95f6589d8434a53c2086f9ad34f9a4a95984362e22a11417d08caaf4cc3e1c8b13230aa24d80bbc6bd65af75a!@mx.jul.es">I'm
running ZendTo 5.17-6 on CentOS Linux release 7.6.1810
<br>
<br>
It's using the 'new' PHPMailer, not the 'old' PHP mail() function.
<br>
<br>
Where does PHPMailer look for root or intermediate certificates
when attempting to STARTTLS? Is this a setting specific to PHP? Or
is it using my system-level CA stores?
<br>
</blockquote>
<br>
<pre class="moz-signature" cols="72">Jules
--
Julian Field MEng CEng CITP MBCS MIEEE MACM
'Infosec: A profession that turns normal people into whiskey drinking,
swearing, paranoid, disheartened curmudgeons with no hope for the
future of computers or humanity.' - Urban Dictionary
<a class="moz-txt-link-abbreviated" href="http://www.Zend.To">www.Zend.To</a>
Twitter: @JulesFM
</pre>
</body>
</html>