So, these are th eresults: 1. A new created maiil does not have a spam tag.
2. Reply to my own mail does also not have a spam tag. 3. Reply to any user mail DOES have a spam tag. So it looks like there is something , which some mailservers do not like. As I am sending only text from me, seldom the text of the users, I suppose, there is something in the header of the mail, which causes this issue. I suppose, I can do nothing else but create a new mail and copy and paste from the received mail of the user. This should avoid the spam tag. Weired thing at all..... Hans