diff --git a/xml/xslt/inline.xslt b/xml/xslt/inline.xslt
index 88efd95..1290131 100644
--- a/xml/xslt/inline.xslt
+++ b/xml/xslt/inline.xslt
@@ -3,7 +3,7 @@
     xmlns:xs="http://www.w3.org/2001/XMLSchema" exclude-result-prefixes="xs" version="2.0">
 
     <xsl:template name="checkLinkValidity">
-        <xsl:if test="not(starts-with(@href, '#')) and not(contains(@href, '://'))">
+        <xsl:if test="not(starts-with(@href, '#')) and not(contains(@href, '://') and not(contains(@href, 'mailto:'))">
             <xsl:call-template name="displayErrorText">
                 <xsl:with-param name="string">[ Invalid link: use #[id] for internal links or a
                     well-formed url for external ones ]</xsl:with-param>