Occasionally, people ask me to edit a comment they have made (usually to cut something out). Sometimes, it is possible to copy a whole comment and then re-post it without losing the sequence of comments - but I can't log in to someone else's ID if they have used a blogger ID.
So please - if you just want to send me a "not for publication" message, please put it in a separate comment that can simply be deleted in its entirety.
The other day, I saw a hack which enables you to edit blogger comments. I might well get round to implementing this. Sometimes, a comment is worth posting but has to be rejected because of one sentence or phrase that is unacceptable.
(BTW if you want a quick way to email me, you can always use the email icon at the bottom of a post. You will end up sending me a copy of my own post as well as your message but I don't mind that. I get quite enough spam already so I don't put the email address as text on the blog.)