I am running my own mail server i.e Exchange server 03 on a basic cable modem connection. I am able to send mail within and outside my domain through dyndns. But somehow i m not able to receive mails from outside like yahoo or hotmail eventhough i hve enable POP3 service on exchange n hve opened all the required ports on my ADSL router. Can anyone help me out plz as how could i receive mails from outside web mail sites like yahoo Thanks in advance

Mitz, let's start out with a really basic question. Did you register an Internet domain, such as mitz.com and then have an Internet MX record that points to your external host name (such as mitz.dyndns.com)? That is how external organizations find you, by looking up your mail server using your MX record in your public domain name. Also, make sure that you have an E2K3 recipient policy that includes @mitz.com (or whatever your public SMTP domain name is.) With respect to your firewall, all you need to open up and allow to your Exchange server is SMTP (port 25).

Hi Jim, Thanks a lot for ur help and do appreciate the way u trying to solve my problem.Before making commentson ur resolution which u wrote for me i would like toexplain the setup which i hve made for my mail server.I have infact registered on dyndnsand been using its service called dynamic DNS. I have created a host service called mitz.dyndns.org and its pointing to my dynamic WAN address and regarding creating MX record i doubt that if idnt create a MX record i wont receive mails bcoz if u checktheir website(dyndns.org) they hve mentioned tht MX records are generally used when incaseanother machine handles the mail. So, for example, we want the machine mail.dyndns.org to handle the mail sent to @dyndns.org, so all we need to do is have an MX for dyndns.org pointing to mail.dyndns.org, then we tell the machine mail.dyndns.org that it handles mail for @dyndns.org, otherwise it'll reject it. If in my case if u see that i hve only one mail serverand there is no need for meto point to my mail server so based on their explaination i dnt need to create a MX record. I dnt knw to what extent this is true but pls if u could explain me about thisthings in more detail it would be a great help.

Unfortunately you are wrong. If you dont have an MX ecord you cannot receive mails. This is just how DNS works. If your dyndns name is mitz.dyndns.org then i can tell you that: No MX records exist for mitz.dyndns.orgAccording to dnsstuff. (I assuming that mitz.dyndns.org is not ficticious in this example).In other words you cant receive mail. If you do setup an MX record you will be able to receive mails, however your problems will not end there unfortunately. Many major email providers refuse to accept mail from people who dont have a static IP address. Hotmail, AOL etc.GMAIL do accept mail, however you have a greater spam rating, so many messages you send will be dropped into peoples spam boxes.For example today your ip address for mitz.dyndns.org was 84.95.90.140. According to spamhaus :84.95.64.0/18 is listed on the Policy Block List (PBL)To get around this problem you will need to ensure that you setup a smart host in exchange. You can get the details for this from your ISP, however not all ISP's offer this feature while others are sticky about it - example BT can get very sticky on this, and require the WHOIS information on the domain that you are sendig mail from to be registered in the same name as the internet. Obviously this is impossible if your domain is registered with dyndns (they dont register the WHOIS in your name AFAIK).Assuming that you get around the problem of sending mail, and can setup an MX record (I dont know how you would do this in dyndns - it could be a paid for service??) you will still be heavily relient on your ISP's mailservers always working f you wanted to send mail. Most ISP's see the mail relay service as a home offering and do not guarantee high uptime on their mail servers. If they are having problems, your mail will not be able to be sent.Having a dynamic IP is both complicated and, relative to the cost of a static IP address (10 pounds extra with BT) and the cost or registering your own domain name (about 20 pounds for 2 years with Yahoo I think) the hassle is normally not worth it. Running a mail server on a dynamic IP address will be sure to cause you problems one day no matter how you set it up.Pete