421 invalid sender domain

[Mazer]

I have some problems with mail in WHM; it appears to fail at points and I have difficulty locating a solution:

Message 1OdGN2-0004Fy-Ms is not frozen
delivering 1OdGN2-0004Fy-Ms
Connecting to mx01.1and1.co.uk [212.227.15.150]:25 ... connected
  SMTP<< 220 mx-b.kundenserver.de (mxbap4) Welcome to Nemesis ESMTP server
  SMTP>> EHLO xxxx.rsclientdns.com
  SMTP<< 250-mx-b.kundenserver.de
         250-PIPELINING
         250-8BITMIME
         250-SIZE 120000000
         250 HELP
  SMTP>> MAIL FROM:<nobody@xxxxx.rsclientdns.com> SIZE=2383
  SMTP>> RCPT TO:<xxxx@xxxxx.co.uk>
  SMTP>> DATA
  SMTP<< 250 OK
  SMTP<< 421 invalid sender domain 'xx.rsclientdns.com' (misconfigured dns?)
LOG: MAIN
  SMTP error from remote mail server after RCPT TO:<xxx@xxxxr.co.uk>: host mx01.1and1.co.uk [212.227.15.150]: 421 invalid sender domain 'mcm.rsclientdns.com' (misconfigured dns?)
  SMTP<< 554 No valid recipients
  SMTP>> QUIT
Connecting to mx01.1and1.co.uk [212.227.15.186]:25 ... connected
  SMTP<< 220 mx-b.kundenserver.de (mxbap2) Welcome to Nemesis ESMTP server
  SMTP>> EHLO xxx.rsclientdns.com
  SMTP<< 250-mx-b.kundenserver.de
         250-PIPELINING
         250-8BITMIME
         250-SIZE 120000000
         250 HELP
  SMTP>> MAIL FROM:<nobody@xxx.rsclientdns.com> SIZE=2383
  SMTP>> RCPT TO:<rxxx@xxxxr.co.uk>
  SMTP>> DATA
  SMTP<< 250 OK
  SMTP<< 421 invalid sender domain 'xx.rsclientdns.com' (misconfigured dns?)
LOG: MAIN
  SMTP error from remote mail server after RCPT TO:<rrpd@robinsonanddicker.co.uk>: host mx01.1and1.co.uk [212.227.15.186]: 421 invalid sender domain 'xx.rsclientdns.com' (misconfigured dns?)
  SMTP<< 554 No valid recipients
  SMTP>> QUIT
Connecting to mx01.1and1.co.uk [212.227.15.169]:25 ... connected
  SMTP<< 220 mx-b.kundenserver.de (mxeu5) Welcome to Nemesis ESMTP server
  SMTP>> EHLO xxx.rsclientdns.com
  SMTP<< 250-mx-b.kundenserver.de
         250-PIPELINING
         250-8BITMIME
         250-SIZE 120000000
         250 HELP
  SMTP>> MAIL FROM:<nobody@xxx.rsclientdns.com> SIZE=2383
  SMTP>> RCPT TO:<xxx@xxxx.co.uk>
  SMTP>> DATA
  SMTP<< 250 OK
  SMTP<< 421 invalid sender domain 'xxx.rsclientdns.com' (misconfigured dns?)
LOG: MAIN
  SMTP error from remote mail server after RCPT TO:<xxx@xxx.co.uk>: host mx01.1and1.co.uk [212.227.15.169]: 421 invalid sender domain 'mcm.rsclientdns.com' (misconfigured dns?)
  SMTP<< 554 No valid recipients
  SMTP>> QUIT
Connecting to mx01.1and1.co.uk [212.227.15.134]:25 ... connected
  SMTP<< 220 mx-b.kundenserver.de (mxeu5) Welcome to Nemesis ESMTP server
  SMTP>> EHLO mcm.rsclientdns.com
  SMTP<< 250-mx-b.kundenserver.de
         250-PIPELINING
         250-8BITMIME
         250-SIZE 120000000
         250 HELP
  SMTP>> MAIL FROM:<nobody@xxx.rsclientdns.com> SIZE=2383
  SMTP>> RCPT TO:<xxxx@xxxxr.co.uk>
  SMTP>> DATA
  SMTP<< 250 OK
  SMTP<< 421 invalid sender domain 'xxx.rsclientdns.com' (misconfigured dns?)
  SMTP<< 554 No valid recipients
  SMTP>> QUIT
LOG: MAIN
  == xxx@rxxx.co.uk R=lookuphost T=remote_smtp defer (-44): SMTP error from remote mail server after RCPT TO:<xxx@xxx.co.uk>: host mx01.1and1.co.uk [212.227.15.134]: 421 invalid sender domain 'xxx.rsclientdns.com' (misconfigured dns?)

[crazyaboutlinux]

I've found 2 errors in the error logs

SMTP<< 421 invalid sender domain 'xxx.rsclientdns.com' (misconfigured dns?)
SMTP<< 554 No valid recipients

Kindly get this checked whether DNS is proper setup or not

And also recipients email id is invalid

554 No valid recipients

[Mazer]

All the nameservers resolve and all domains are working. The host of this server has a seperate nameserver that then sends them to our server.

[dreas]

SMTP<< 554 No valid recipients: This has nothing to do with your server. 1und1 is rejecting the email because the recipient doesn't exist.


SMTP<< 421 invalid sender domain 'xx.rsclientdns.com' (misconfigured dns?): It appears the sending domain doesn't resolve. I presume xx.rsclientdns.com is a fake domain? Can you PM the real log so I can check it for you?

[Mazer]

I have it sorted now - creating name servers and mx entries on the site were moot as they were resolved elsewhere, logged into hosting site and resolved the issue

is there a mark as solved type thing on this forum?