id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc,focuses 39775,wp_mail miss send Content-Type with boundary when array header does not have other custom headers,kn007,,"It's a PR send in github. https://github.com/WordPress/WordPress/pull/273 Fix empty charset in line 436. Before: `Content-Type: multipart/alternative; charset=` After: `Content-Type: multipart/alternative; charset=UTF-8` ------------- fix `$headers[] = ""Content-Type: multipart/alternative; boundary=\""$boundary\"""";` not send when not other headers. Test Code: {{{#!php ""; $headers[] = ""Content-Type: multipart/alternative; boundary=\""$boundary\""""; $body = ""--$boundary\r\n"" . ""Content-Type: text/plain; charset=UTF-8\r\n""; $body .= 'test'; $body .= ""--$boundary\r\n"" . ""Content-Type: text/html; charset=UTF-8\r\n""; $body .= '
test
'; wp_mail( $to, $subject, $body, $headers ); }}} Before: [[Image(https://cloud.githubusercontent.com/assets/6196903/22583305/a84c5f1c-ea26-11e6-8718-2bde99d20484.png)]] After: [[Image(https://cloud.githubusercontent.com/assets/6196903/22583326/c4055362-ea26-11e6-8890-1da8fac8552e.png)]] I could search some issue for this, like http://wordpress.stackexchange.com/questions/191923/sending-multipart-text-html-emails-via-wp-mail-will-likely-get-your-domain-b https://wordpress.org/support/topic/using-wp_mail-with-php-generated-attachments/ but still have same problem here.",defect (bug),new,normal,Awaiting Review,Mail,,normal,,,,