>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #906838. --> Reported by: [reinvented](https://www.drupal.org/user/17600) >>> <p>The <a href="http://api.drupal.org/api/function/drupal_mail">drupal_mail</a> documentation says, in reference to the 'To' address:</p> <blockquote><p> The e-mail address or addresses where the message will be sent to. The formatting of this string must comply with RFC 2822. Some examples are: <a href="mailto:user@example.com">user@example.com</a> <a href="mailto:user@example.com">user@example.com</a>, <a href="mailto:anotheruser@example.com">anotheruser@example.com</a> User &lt; <a href="mailto:user@example.com">user@example.com</a>&gt; User &lt; <a href="mailto:user@example.com">user@example.com</a>&gt;, Another User &lt; <a href="mailto:anotheruser@example.com">anotheruser@example.com</a>&gt; </p></blockquote> <p>I take this to mean that I should be able to set the $to parameter to something like:</p> <div class="codeblock"> <pre><span style="color: #000000"><span style="color: #0000BB">&lt;?php<br>$to </span><span style="color: #007700">= </span><span style="color: #DD0000">"test1@example.com,test2@example.com"</span><span style="color: #007700">;<br></span><span style="color: #0000BB">drupal_mail</span><span style="color: #007700">(</span><span style="color: #DD0000">'module'</span><span style="color: #007700">,</span><span style="color: #DD0000">'key'</span><span style="color: #007700">,</span><span style="color: #0000BB">$to</span><span style="color: #007700">, </span><span style="color: #0000BB">$language</span><span style="color: #007700">, </span><span style="color: #0000BB">$params</span><span style="color: #007700">);<br></span><span style="color: #0000BB">?&gt;</span></span></pre></div> <p>This <i>does</i> work -- both recipients get the email -- with the standard Drupal mailer used to send the mail.</p> <p>However if I try to do the same thing with Postmark installed as the mailer, only the <i>final</i> address gets the mail.</p> <p>This is because the Postmark module sets the 'To' address with:</p> <div class="codeblock"> <pre><span style="color: #000000"><span style="color: #0000BB">&lt;?php<br></span><span style="color: #007700">foreach (</span><span style="color: #0000BB">postmark_parse_address</span><span style="color: #007700">(</span><span style="color: #0000BB">$message</span><span style="color: #007700">[</span><span style="color: #DD0000">'to'</span><span style="color: #007700">]) as </span><span style="color: #0000BB">$address</span><span style="color: #007700">) {<br>&nbsp; </span><span style="color: #0000BB">$mail</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">to</span><span style="color: #007700">(</span><span style="color: #0000BB">$address</span><span style="color: #007700">[</span><span style="color: #DD0000">'mail'</span><span style="color: #007700">], </span><span style="color: #0000BB">$address</span><span style="color: #007700">[</span><span style="color: #DD0000">'name'</span><span style="color: #007700">]);<br>}<br></span><span style="color: #0000BB">?&gt;</span></span></pre></div> <p>Rather than being <i>additive</i>, this code simply serves to <i>overwrite</i> the 'To' address every time through the loop.</p> <p>It seems that the <a href="http://github.com/Znarkus/postmark-php">Postmark.php</a> class upon which the Postmark module depends does not, in fact, support sending multiple 'To' addresses. For example, this will fail:</p> <div class="codeblock"> <pre><span style="color: #000000"><span style="color: #0000BB">&lt;?php<br>$email </span><span style="color: #007700">= new </span><span style="color: #0000BB">Mail_Postmark</span><span style="color: #007700">();<br></span><span style="color: #0000BB">$email</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">from</span><span style="color: #007700">(</span><span style="color: #DD0000">'from@example.com'</span><span style="color: #007700">, </span><span style="color: #DD0000">'From Name'</span><span style="color: #007700">);<br></span><span style="color: #0000BB">$mail</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">to</span><span style="color: #007700">(</span><span style="color: #DD0000">"test1@example.com,test2@example.com"</span><span style="color: #007700">);<br></span><span style="color: #0000BB">$email</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">subject</span><span style="color: #007700">(</span><span style="color: #DD0000">'Subject'</span><span style="color: #007700">);<br></span><span style="color: #0000BB">$email</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">messagePlain</span><span style="color: #007700">(</span><span style="color: #DD0000">'Plaintext message'</span><span style="color: #007700">);<br></span><span style="color: #0000BB">$email</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">send</span><span style="color: #007700">();<br></span><span style="color: #0000BB">?&gt;</span></span></pre></div> <p>with an "Fatal error: Uncaught exception 'Exception' with message 'Invalid to address'" exception.</p> <p>I've filed an <a href="http://github.com/Znarkus/postmark-php/issues/issue/1">issue at github</a> regarding the Postmark class.</p> <p>I'm not sure what to recommend otherwise, but this is a serious issue because there are many places in Drupal that support multiple 'To' addresses, and thus assume the mailer is capable of handling them.</p>