diff --git a/app/src/main/java/eu/faircode/email/HtmlHelper.java b/app/src/main/java/eu/faircode/email/HtmlHelper.java
index 10fa581d46..a02dc62eb1 100644
--- a/app/src/main/java/eu/faircode/email/HtmlHelper.java
+++ b/app/src/main/java/eu/faircode/email/HtmlHelper.java
@@ -456,6 +456,7 @@ public class HtmlHelper {
                 .removeAttributes("th", "colspan", "rowspan", "width")
                 .addProtocols("img", "src", "cid")
                 .addProtocols("img", "src", "data")
+                .removeProtocols("a", "href", "ftp")
                 .addProtocols("a", "href", "full", "xmpp", "geo", "tel");
         if (text_color)
             whitelist.addAttributes("font", "color");