sendmail newbie - utterly lost !! -

Posted on 2006-05-16
Last Modified: 2013-12-17

i'm seriously struggling with setting up a network at home - so much for ambition !!

i have a fedora core 5 box acting as a PDC with a RAID 1 array and am using mdadm to monitor the array

i need to send mdadm alerts via email but can't get it to work ............ here's the setup

static IP:
hostname: boomslang

i have a Smoothwall box (internal IP which does DHCP for the rest of the network

to test the sendmail (which mdadm uses for the alerts) i use

echo "testing neill mail" | mail -s "testing" neill
(neill is a user on the PDC)

in /etc/aliases i have the entry

sysadmin is set up as a mailbox at my ISP and i can send and receive fine from that mailbox (using t'bird from an XP machine)

when i run the sendmail test as root ithe PDC i get a 550 error as below: (email addresses edited)


The original message was received at Tue, 16 May 2006 23:35:20 +0100
from localhost.localdomain []

   ----- The following addresses had permanent fatal errors -----
    (reason: 550-Verification failed for <root@localhost.localdomain>)
    (expanded from: <neill@localhost.localdomain>)

   ----- Transcript of session follows -----
... while talking to

>>>>>> DATA

<<< 550-Verification failed for <root@localhost.localdomain>
<<< 550-REJECTED: Cannot route message
<<< 550 Sender verify failed
550 5.1.1 User unknown
<<< 503 valid RCPT command must precede DATA

Reporting-MTA: dns; localhost.localdomain
Received-From-MTA: DNS; localhost.localdomain
Arrival-Date: Tue, 16 May 2006 23:35:20 +0100

Final-Recipient: RFC822; neill@localhost.localdomain
X-Actual-Recipient: RFC822;
Action: failed
Status: 5.1.1
Remote-MTA: DNS;
Diagnostic-Code: SMTP; 550-Verification failed for <root@localhost.localdomain>
Last-Attempt-Date: Tue, 16 May 2006 23:35:20 +0100

root <root@localhost.localdomain>
Tue, 16 May 2006 23:35:20 +0100

testing neill mail


i get a similar error if i run the mdadm test command

mdadm --follow --scan --daemonise --delay=10 --test

this means zip to me !! ;(

i'm clearly missing something obvious but i've read some sendmail FAQs, docs and the like and am now simply more confused than ever

anyone able to help me out please ?

Question by:babysnake

    Author Comment


    a long noght reading through the forums gives me this ....

    my ISP cannot resolve root@localhost.localdomain ... fair enough

    so it rejects the mail as 'unrouteable'

    how do i get round this ?

    (i accept i get the message, insofar as i get an error with the message attached, but aesthetics and education demand i fix this - or is it unfixable in this environment ?)
    LVL 6

    Accepted Solution

    The remote host refuses to accept messages from sender without internet reachable domain [localhost.localdomain]. The check has been widely added as one of anti-spam prevention measures.

    Make your hosts know and report its proper internet name.

    Author Comment

    thanks anfi

    i'll try that

    Featured Post

    Don't lose your head updating email signatures!

    Do your end users still have the wrong email signature? Do email signature updates bore you or fill you with a sense of dread? You can make this a whole lot easier on yourself by trusting an Exclaimer email signature management solution. Over 50 million users should you!

    Join & Write a Comment

    When it comes to providing great business solutions, IBM and Microsoft are the two top companies excelling in the art. Both launch similar products aimed at a wide audience set and have a good customer satisfaction rate. Since their products are qui…
    Resolve Outlook connectivity issues after moving mailbox to new Exchange 2016 server
    In this video we show how to create a Distribution Group in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Recipients >>…
    In this video we show how to create a mailbox database in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Servers >> Data…

    745 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    16 Experts available now in Live!

    Get 1:1 Help Now