Exchange 5.5 and Undeliverable mail

[mindwaves]

I have been running an exchange 5.5 server on Windows 2000 for a few months now without too many issues in a very small organization. Recently we have been getting several emails coming back as undeliverable.

One of the issues that I was able to drag up is that we are blocked from some domain's automatically because we do not have a static IP. I am using a POP connector to retrieve our email from our mail provider.

I had an open relay as well, which I have now closed off thanks to the posts I have read on this site.

Where do I go from here?

 

[xmario2013]

is there any reason why you don't use a static ip ?

do you have a stable conneection or just modem ?

yes alot domain these days are scare of spam so they block certain host without a static ip its possible anyway

measuring the pro and con, if you figure it just a few emails get bounced not 90% you can probably deliver with some other method (ie. yahoo email account), if you don't want to worry about you should start plan to setup IMC (internet mail connector) and talk to your isp

 

[mindwaves]

Thanks for the assistance xmario2004, I am contacting my ISP for a static IP, there was no major reason why we did not use static IP, just the way the account was set up.

Is there anything else I should be checking for being blocked?

 

[rdroske]

Your IP should not matter if your email is being delivered to a third party provider. In that case the MX record for your domain will point to the providers server. Do an nslookup on your domain to verify.


Also in that case you don't need to open SMTP traffic to your server to the internet (TCP port 25) so it should also not matter if your server is an open relay.

 

[mindwaves]

Sorry, I left out the fact that I am using IMC to deliver mail, my mail provider does not support outgoing SMTP. Is there a third party piece of software that I need to deliver the emails back through my ISP, or is there something in the IMC that I can configure to do that and are there any drawbacks to this?

 

[rdroske]

Ok, that does change it a bit.

If you deliver it yourself then you will need a fixed IP because of the reverse DNS lookup that some sites require before accepting mail. When you get one from your ISP make sure that they set up Reverse DNS to work correctly for it.