I have installed new hardware on a server and installed 7.51 about a month ago. Before I changed the hardware (maybe earler version 7) I just used the "Select dynamic DNS service" feature in the shell gui in the past and it seemed to work. 
However unless i have it set up wrong, (a possibiility ) I'm not sure its working now. I have read several posts regarding this kind of problem and some seem to say this does not work any more. (Btw I have a free account at dyndns.)
Other say you MUST download software to get it to work. 
the current configuration setting that Im using is 
First screen you enter your account name e.g DogFace1
Then the Password in the second screen. 
Is that right or am I wrong?? Sadly I wiped away the old server before looking at it to see how I set it up.
My free dyndns account has two domains in it. eg hello.dyndns.info and goodbye.dyndns.info.
Im confused how in the past, the sme server know which dyndns name to use. eg hello.dyndns.info or goodby.dyndns.info. I also saw comments that if you needed two domains then you had to use the software, HOWEVER, I though this was only if the SME server needed two domain.  Not if there were two names in the dyndsn account.
 concerned.
Finally I tried running (see below the command and errors)
But got some errors. Again I see that there are some posts regarding this particularly in the bug reports and am sure I have over looked the answer, and cant find it. There seems to be alot of info and Im confused.
My questions then are.
1. Can i use ddns out of the box? or does that not work. I expect no fix as version 8 is out. Just like to know, I prefer this solution. Should I delete a dyndns address from dyndns eg hello.dyndns.info ??? Or just not try cause it doesnt work .
2. If I have to use a contrib which should I use that works? or how should I deal with the problems I have below. I dont think I have installed the .fr edition that is mentioned that needs to be uninstalled, as mentioned in several posts.
As always 
Regards
[root@server ~]# yum --enablerepo=smedev install sme7-ddclient
Loading "installonlyn" plugin
Loading "smeserver" plugin
Loading "protect-packages" plugin
Loading "fastestmirror" plugin
Setting up Install Process
Setting up repositories
smedev                    100% |=========================| 2.3 kB    00:00
smeaddons                 100% |=========================| 2.3 kB    00:00
smeextras                 100% |=========================| 2.3 kB    00:00
smeos                     100% |=========================| 2.3 kB    00:00
smeupdates                100% |=========================| 2.3 kB    00:00
Loading mirror speeds from cached hostfile
Reading repository metadata in from local files
primary.xml.gz            100% |=========================|  41 kB    00:00
smedev    : ################################################## 138/138
http://distro.ibiblio.org/pub/linux/distributions/smeserver/releases/7/smeaddons                               /i386/repodata/primary.xml.gz: [Errno 14] HTTP Error 403: Forbidden
Trying other mirror.
primary.xml.gz            100% |=========================|  84 kB    00:00
http://mirror.pialasse.com/releases/7/smeaddons/i386/repodata/primary.xml.gz: [E                               rrno -3] Error performing checksum
Trying other mirror.
primary.xml.gz            100% |=========================|  84 kB    00:01
http://mirror.ovh.ifec.net/releases/7/smeaddons/i386/repodata/primary.xml.gz: [E                               rrno -3] Error performing checksum
Trying other mirror.
primary.xml.gz            100% |=========================|  84 kB    00:00
http://mirror.chiropratique.org/releases/7/smeaddons/i386/repodata/primary.xml.g                               z: [Errno -3] Error performing checksum
Trying other mirror.
primary.xml.gz            100% |=========================|  92 kB    00:00
http://aubrac-medical.fr/releases/7/smeaddons/i386/repodata/primary.xml.gz: [Err                               no -3] Error performing checksum
Trying other mirror.
primary.xml.gz            100% |=========================|  84 kB    00:00
http://mirror.absolutnet.de/releases/7/smeaddons/i386/repodata/primary.xml.gz: [                               Errno -3] Error performing checksum
Trying other mirror.
primary.xml.gz            100% |=========================|  84 kB    00:01
http://mirror.hakkers.com/releases/7/smeaddons/i386/repodata/primary.xml.gz: [Er                               rno -3] Error performing checksum
Trying other mirror.
primary.xml.gz            100% |=========================|  84 kB    00:01
http://sme-mirror.firewall-services.com/releases/7/smeaddons/i386/repodata/prima                               ry.xml.gz: [Errno -3] Error performing checksum
Trying other mirror.
primary.xml.gz            100% |=========================|  84 kB    00:00
http://mirror.drogisterij-markt.nl/sme/releases/7/smeaddons/i386/repodata/primar                               y.xml.gz: [Errno -3] Error performing checksum
Trying other mirror.
primary.xml.gz            100% |=========================|  84 kB    00:00
http://ftp.nluug.nl/os/Linux/distr/smeserver/releases/7/smeaddons/i386/repodata/                               primary.xml.gz: [Errno -3] Error performing checksum
Trying other mirror.
primary.xml.gz            100% |=========================|  84 kB    00:00
http://ftp.surfnet.nl/ftp/pub/os/Linux/distr/smeserver/releases/7/smeaddons/i386                               /repodata/primary.xml.gz: [Errno -3] Error performing checksum
Trying other mirror.
Error: failure: repodata/primary.xml.gz from smeaddons: [Errno 256] No more mirr                               ors to try.