Topic: Emails get rejected

[weblance]

Hi guys

Just to make sure that the problem isn't mine, so I'm asking you guys.

I have my SME installed in Denmark, and i'm having a lot of problems sending email to some of my german colleagues. They don't receive my emails. I get a failure notice from the mailer daemon:

Connected to xxx.xxx.xxx.xxx but greeting failed.
Remote host said: 554 RBL rejection: local dynamic IP address xxx.xxx.xxx.xxx I'm not going to try again; this message has been in the queue too long.

I'm also getting some errors from some of my customers. They get a rouing error when they try to send me emails.

Can you please tell me what might be wrong, and is it my problem? All these prosblems started about 14 days ago, when my company changed ISP. I know that this probably is the source of the routing error issue, but is it also the reason why i get the 554 RBL rejection?

I really hope you guys can help.

/Carl

[cactus]

Does your provider do this often or was this a one time change? Did you update your DNS accordingly? Are you using a service like dyndns (handy for when your provider is doing this often when you have a dynamic IP address?

According to the error message the problem is on the remote site, it can be caused by your configuration though.

[cactus]

It might also be that your new IP address was once used to send spam and that IP address is blacklisted on a RHBL site. You will have to find out which sites the remote party is using and have your IP removed from the list.

[cactus]

This might also help: http://www.mxtoolbox.com/blacklists.aspx

[Stefano]

Hi guys

Just to make sure that the problem isn't mine, so I'm asking you guys.

I have my SME installed in Denmark, and i'm having a lot of problems sending email to some of my german colleagues. They don't receive my emails. I get a failure notice from the mailer daemon:

use your ISP's smarthost to send email
from server-manager -> Email -> Change Email delivery settings

I'm also getting some errors from some of my customers. They get a rouing error when they try to send me emails.

this is a different issue.. related but different.. please, next time open 2 different topics, thank you
if your MX record is pointing to a dynamic ip address you can have such a problem.

[weblance]

I've been in contact with the receivers ISP and they say that the problem is that my server has an dynamic DHCP IP address. I told this to my ISP and they have changed the reverse DNS. This haven't helped so do you guys have any idea?

[Brave Dave]

If you ip is dynamic, you will have erratic results sending and probably be blocked most of the time, you need to forward outbound email to your ISP

Incoming to Dynamic will work, but again not reliably
If the IP is reallocated to someone else with an open SMTP port, your email will get rejected
If the IP is reallocated to someone else with an open SMTP port, your email will get delayed - at best

you need to make sure the ttl is dynamic - use dig

dig +nocmd gmail.com MX +noall +answer

and you will see gmail is 3600 - thats 1 hour, yours should be 60 (1 minute)

[beakersloco]

Your problem is that you will need to get a static ip address in order to be able to send email and your friends receive it. The problem is that spammers like to setup shop and send emails from dynamic ip addresses making then harder to catch... because of this you will need to get a static address in order to send emails.

You also need to get an account at http://www.dyndns.com/  this way you have a domain name for the email to route to you.  Once you get an account setup with dyndns then you simply go into your setup and add in the account name and password.  If you need help let me know and I can whip up a workstep with more detailed info. 

[weblance]

I have had this dialogue with my ISP. I have a domain name for my mailserver, and I've told my ISP that I want a static IP address, but they just reject my request and they don't understand why my current IP is rejected. They have altered the reverse DNS, but it still doesn't work.

[Brave Dave]

Well - I think that says it all

With my ISP the static IP is a additional charge - and quite considerable charge now because IPV4 ips are scarcer

If you haven't an option to purchase one, maybe your ISP can't offer it. ... time to .. ? change ?

[weblance]

I have asked for a static ip but they just rejected my request saying that my dynamic ip is just as good as a static.

[Brave Dave]

Sure, but there are specific RBL lists which filter dynamic IPs - and a lot of us use them - but you can't sit on a dynamic ip and wonder what the problem is - you know

[weblance]

Sure, but there are specific RBL lists which filter dynamic IPs - and a lot of us use them - but you can't sit on a dynamic ip and wonder what the problem is - you know

Exactly!

I'm now trying to send though my ISP's smarthost . . . and x my fingers.

[MSmith]

You might want to add an SPF record for your domain authorizing your ISP's smarthost to send emails on your domain's behalf.

[beakersloco]

I have had this dialogue with my ISP. I have a domain name for my mailserver, and I've told my ISP that I want a static IP address, but they just reject my request and they don't understand why my current IP is rejected. They have altered the reverse DNS, but it still doesn't work.

If they dont understand ... then is sounds like you need to find another ISP. As the one you have is apparently a small one and their staff either dont fully understand the issue or because of what you are telling them they realize that you dont fully understand how its supposed to work so they snowball you with that BS.Telling them the error message "Remote host said: 554 RBL rejection: local dynamic IP address xxx.xxx.xxx.xxx" should fully explain to them  the reason why you need a static ip and if they dont understand that they should not be running an ISP.

Now from reading what I have read on this thread I suspect that you have something misconfigured  on your end as you will always be able to receive emails if your dns is setup properly unless they(ISP) are blocking that port, but I doubt that.  I would say this is the time for you to start hunting for a new service provider  who can provide you with a static ip. 

On to the problem at your end .... your dns is not setup properly because if it was you would be able to receive emails ... despite the fact that your ip is dynamic and changing. I would recommend setting up a free dyndns account, get it working then try again to set up using your dns name. Fully read the instructions below.

Setup a free account with http://www.dyndns.com/ .... configure your server and you can test it yourself by using an account via your ISP  email or using a free web based service like hotmail or yahoo to test.    if its still not working then follow the steps below.

Steps you need to do after setting up a free DYNDNS account.  Log into your server console using putty or goto the system .. log in using the admin account.

Go into your server console.
Option 2 Configure this server
Enter in the default domain name
(enter in the pc name.domain name you choose on dyndns)hit next,
enter in the same PC Name you used above. hit enter
Everything else should be correct so hit enter until you get to the Operation mode.
It should be Option 1 Server and gateway. Hit next
Option 1 Server and gateway - dedicated  hit next
Untill you get to the Choose which DNS service (if you have dyndns)
Option 4 , hit enter and enter in your accountname hit enter
Enter your password and from there everything else should already be setup.
Towards the end there is a place for corporate DNS server address ...I left this blank on

I have been running my setup like this for the past 8 plus years. I initially had issues with the hostname setup and I fixed my issue by putting my pcname in front of the provided dns names. I suspect you have a similar issue.


I dont use the email because I have the same issue that you have, I dont have a static IP, I could get one but I dont want to pay the extra cost. If you have your dns setup properly then you should be able to receive emails with no issue.  There are other things you can also use to test to see of your dns is setup properly .. put a webpage on your server. If a user can access it using your dns name then there is not a problem.

I run a personal webpage on my sme server and I also use my dns name to ftp into my server or vpn into my network.  If your dns is setup properly even with a changing ip address you should be able to use the domain name to send yourself emails , ftp etc.  Something else that I also think may be an issue is that your dns may be slow to renew when your ip address changes.

You may want to find a friend who can help you with this as its a little easier to troubleshoot when someone outside your network is sending you emails. You also may want to setup a webpage because as long as your webpage is viewable then your machine should be able to receive email as well. Hope this helps .. pm me or post to the thread and I will help out as much as I can.

[weblance]

On to the problem at your end .... your dns is not setup properly because if it was you would be able to receive emails ... despite the fact that your ip is dynamic and changing. I would recommend setting up a free dyndns account, get it working then try again to set up using your dns name. Fully read the instructions below.

I don't have any problems receiving emails, never had. The problem was that some mail servers RBL my IP.

And yes, our new ISP is a small one, but they are the only provider here where we can get fiber.

[beakersloco]

Well you did mention that some of your customers get a routing error when trying to send you emails. That to me points at either the DNS is not setup properly or its not refreshing fast enough after your ip address changes.

Quote
    I'm also getting some errors from some of my customers. They get a rouing error when they try to send me emails.

I would say that at the moment they you will have to be patient with the isp while they grow. Let then know that you want a static IP as soon as one becomes available.

[cactus]

You also may want to setup a webpage because as long as your webpage is viewable then your machine should be able to receive email as well.

It might hold up for most setups, but that is not completely true. Since IP numbers for webservers are resolved using CNAME and A records, mail servers are configured using MX and A (and PTR) records. Both A records need not be the same, but sometimes are in case mail server and web server are run at the same host.

Here is some more information on DNS and mail servers: http://www.ipswitch.com/support/imail/guide/imailgsv8.1/Appendix%20A%20dns4.html

[beakersloco]

It might hold up for most setups, but that is not completely true. Since IP numbers for webservers are resolved using CNAME and A records, mail servers are configured using MX and A (and PTR) records. Both A records need not be the same, but sometimes are in case mail server and web server are run at the same host.

Here is some more information on DNS and mail servers: http://www.ipswitch.com/support/imail/guide/imailgsv8.1/Appendix%20A%20dns4.html

I stand corrected then.