Bug 195423

Version:           1.11.3 (using KDE 4.2.3)
OS:                Linux
Installed from:    Fedora RPMs

I'm using qmail with rblsmtpd using spamhaus.org. My SMTP setup is:

TLS
SMTP-AUTH
CRAM-MD5
Store password (if it matters)

When sending mail, I get:

Sending failed:
Invalid SMTP response (0) received.
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 was used:
 my.transport

which wasn't really helpful. What was weird is that it worked at work, but not from home. So, I tried to telnet to my host's 25 and keep getting:

451 http://www.spamhaus.org/query/bl?ip=X.X.X.X

where X.X.X.X is my current IP. Reading spamhaus' info:

"Important: If you are using any normal email software such as Outlook, Entourage, Thunderbird, Apple Mail, and you are being blocked by this Spamhaus PBL listing when you try to send email, the reason is simply that you need to turn on "SMTP Authentication" in your email software settings (Tools : Accounts : Properties : Outgoing Mail Server : check "My server requires authentication")."

If I disable rblsmtpd, kmail sends mail just fine. So, the problem is: either my server is misconfigured (possible, it was done through Plesk) or Kmail doesn't handle this case well. In any case, that error message mentioned could use a facelift, it didn't give me much to go on.