Today, I spend 3 hours to analyse a nasty dtml-sendmail bug (Zope 2.1.6): Zope reported an SMTP exception: "recipient required" It turned out that the "messageText" that arrived in "Products.MailHost.MailHost.send" started with an empty line. Therefore, "decapitate" could not find the "To:", "From:" and "Subject:" headers and called "smtplib.send" with an empty "to" list. What really confused me: my DTML code did not show any sign, where this empty line should come from. Moreover, an identically locking DTML object worked as expected. Explanation: A collegue had edited the DTML object causing the problems with a *WINDOWS* editor and then uploaded the file. The Windows editor had added a Control-M after the "<dtml-sendmail mailhost=...>". This Control-M caused the spurious empty line. In the edit view, the browser did not show the Control-M. Therefore, the faulty and the correct DTML objects looked completely identical. I verified that the same bug is in Zope 2.2.4b1, too. Furthermore, the check for missing "To" and "From" is ineffective (as "extractHeader" always adds a "To" and "From" to header, just empty if it can not find the headers). I will put this into the collector. Dieter