501 invalid domain name -- when trying to send mail (SMTP)
 

Hi,

I am fairly new to linux, and I have been using Kmail (1.7) on KDE 3.3 with SuSE 9.1 as my distro. A problem just arose when I try to send mail via Kmail, and I cannot figure out why.

When trying to send, I get an error message that says:

Sending failed:
Unknown error
Unexpected server response to EHLO command.
The server responded: "5.0.0 EHLO requires domain address"
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.
The following transport protocol was used:
RR

---
I receive mail just fine, and strangely enough, right after I open Kmail, it will send my email, but it will get the error every time after that.

I have tried:
"$ telnet <my.smtp.server> 25"
"ehlo foo at bar"

And I get:
501 5.0.0 Invalid domain name

Has anyone heard of this?? Or can anyone get me on track having my email sent consistently?

Thanks a bunch!
Kevin

Sounds like you haven't configured your client correctly. Normally your isp will specify the address of their smtp server for outgoing mail and the pop3 address for incoming usually in the format inmail.isp.com for smtp and outmail.isp.com for pop3. Check the configuration under Settings -> Configure Kmail ->network and make sure that they are what your isp has given you.

I've double checked the server names, and they are in fact correct (mail will occasionally/rarely send properly). As I mentioned earlier, I had been happily using Kmail for months without any problems and without changing the server names when the error started to occur. Weird eh?

Thanks for your help!

Kevin

Then suspect a server problem with the isp. Check their status and see if they have issued a notice about server problems.

I, too, suspected that (even though its usually MY problem). So I checked on a Windows box in my house which also uses the same SMTP server with Outlook, and it worked flawlessly. Grr...

again, I appreciate any help that can be provided..

Kevin

I am willing to bet they use a linux based server and you can check what they are using via http://www.netcraft.com . The client/os should not affect the way mail is handled.

bumping...b/c problem is back
 

I am back to the original problem as stated in my first post. I never really "fixed" the problem the first time. I basically switched to Thunderbird for awhile, and when I came back to Kmail, email sent flawlessly.

Now, I am back to the same error message. When I telnet into the SMTP server, I can get the same error if I type only "EHLO" and do not include my domain name. I am guessing this is what Kmail is doing, and I'm curious as to how to fix it.

I have the "default domain" properly set in Kmail, and I have toyed with "Custom Hostname to no avail. Can anyone shed some light on this topic?? I've searched extensively and come up with nothing.

Thanks in advance,

Kev

The HELO that you send is incorrect. Most likely, your comuter has a hostname with an invalid character in it, probably a space.

We had this error, and it turned out to be caused by a typo in the hosts file. The "hostname with an invalid character in it" post was the clue. Thanks.