XML Journal: XMLJList  
   XML Journal's XML mailing list community for XML discussions, and technical questions.
   http://www.sys-con.com/xml/list.cfm

ietf-xml-mime  
   Mailing list for discussing MIME types for XML.
   http://www.imc.org/ietf-xml-mime/index.html

DocBook: Mailing Lists  
   Choose from four mailing lists about OASIS DocBook.
   http://www.oasis-open.org/committees/docbook/mailinglist/index.shtml

ebXML mailing lists  
   OASIS hosts two mail lists to provide the public with continuing information on ebXML and faciliate open discussion of the specifications: ebXML announcements and ebXML discussions.
   http://www.ebxml.org/participate.htm

XML Apache mailing lists  
   Home of the xml.apache.org Announcement and General Discussion Lists, Xerces-J User and Developer Lists, Xerces-C Developer List, Xerces-P Developer List, Xalan Developer List, FOP Developer List, Zang Developer List, SOAP User and Developer Lists, and Ba
   http://xml.apache.org/mail.html

ONLamp.com: PHP-XML Mailing List  
   Creation of this list inspired by a passing mention of the dearth of tools for and lack of discussion of PHP and XML despite the incredible popularity of each technology individually
   http://www.onlamp.com/pub/a/php/php-xml-ml.html