diff --git a/modules/markdown/markdown.go b/modules/markdown/markdown.go
index 7458186f0..9e42d072d 100644
--- a/modules/markdown/markdown.go
+++ b/modules/markdown/markdown.go
@@ -43,7 +43,7 @@ func BuildSanitizer() {
 	Sanitizer.AllowURLSchemes(setting.Markdown.CustomURLSchemes...)
 }
 
-var validLinksPattern = regexp.MustCompile(`^[a-z][\w-]+://`)
+var validLinksPattern = regexp.MustCompile(`^[a-z][\w-]+://|^mailto:`)
 
 // isLink reports whether link fits valid format.
 func isLink(link []byte) bool {