Having a static IP won't necessarily help! I have one but people like GMX still reject me. One of the e-mail rules is that your IP must have a PTR record. This is something your ISP controls. GMX will reject generic isp-created PTR records such as static-84-9-57-48.vodafonexdsl.co.uk, and Vodafone won't let me change it even though I am a business customer. For them to allow me to change it I need to take a static block of 8 IP's. Then they will let me have control. Although this blocking is outside the RFC's, there is nothing I can do about it. One of the ways round is to use an SMTP relay. There are a number of free ones - google "SMTP relay free", but I think they will often add a footer to your e-mail to advertise their services.

The other way round the problem is to use your ISP's mail servers. If you ISP offers mail services, they will have an SMTP server for sending out e-mails and you can generally relay via them. If they do not rewrite the "from" or "reply-to" header (I think Google rewrites it) then you can use them and it is better if you can use them un-authenticated. For example, if you are with Virginmedia, from inside their network you can use smtp.ntlworld.com unauthenticated or smtp.virginmedia.com authenticated as a relay.

Yes of course I meant ip not dns. I checked in due time using various tools such as MX lookup! But I didn't know of the existence of services like TURBOsmtp, very expensive though! It is worth changing the current FTTH contract from dynamic to static !!!!

The DDNS is not blacklisted. Your IP is. Just about all dynamic IP's are. To send e-mails you'll need an SMTP relay service such as TurboSMTP. There are free ones but I think they generally add a footer to all your e-mails.

Thanks. Some time ago I tried to use the clearos ddns and actually received the mail but I could not send anything because it was blacklisted! Is the software you talk about Mail Retrieval? From what I understood he was only receiving emails, not sending them too, I'll try it tomorrow!

ClearOS has a mail retrieval app which I believe does what you want. It can retrieve mail from POP and IMAP accounts.

Having said that, I believe you can still use ClearOS as a local mail server. Your poweredbyclear.com DDNS is an A record so can be used as your MX record. If you use Clearcenter as your domain registrar, you even get a backup MX if you really want it. You will still need an SMTP relay for sending e-mail out unless you want some MTA's to block it (e.g. GMX) or others to treat it as spam as you will be automatically on the SORBS blacklist.