I am using KMail and am able to receive email OK.
When I try to send an email I get the following error each time

Sending failed:
The server did not accept the sender address.
The server responded: "5.5.4 <MAILER-DAEMON>... Domain name required for sender address MAILER-DAEMON "
The message will stay in the 'outbox' folder until you either fix the problem (e.g. a broken address) or remove the message from the 'outbox' folder.
Note: Other messages will also be blocked by this message, as long as it is in the 'outbox' folder
The following transport protocol was used:
Stelle Send Mail

I have checked settings and believe that everything is OK.
My login is OK
My password is OK
Im not sure about the port option..it defaulted to 25
I receive on port 100 ...whatever that means


Any ideas?

go to k-mail settings tab and then check your identity. You have to supply an email address for yourself that at least looks like one.

I to am unable to send mail in kmail,in mandrake 10 . My identity is set up ok and my email is my email,so i downloaded and set yp thunderbird 6 with no problems,until I can get this setting in kmail figured out,as I think I would like kmail.

That is my problem exactly. I can send mail with evolution and mozilla, but kmail won't send. I have my identity set up correctly as far as I can see.

In many instances servers will back-check for the validity of the sender's email address, and if missing, or it can't be found, the server will take it as spam mail, and block the message. You have to create a presence on the internet to be valid. Sendmail would not show a valid return email address that can be traced. I use a free service on the internet, that changes my dynamic IP address into a fixed URL. The service generates and provides all the files needed on their server so that emails can be checked and validated.

Thanks for the response ONEderer, I would imagine that you are correct, however I don't have the slightest idea what all that meant

Any chance you could explain what exactly I should do in simpler and step by step terms?

Thanks

Fixed the problem ,at least for me,apparently my server doesn't accept authentication,simply unchecking the box in settings for smtp settings did the trick!! This must have been the default setting as I don't rember doing it myself. Hope thers fix as easy. Regards to all