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Exchange and DDNS? Possible?

26 posts in this topic

Posted

im wondering if i can have exchange emails with ddns. such as have my own exchange server and my own ddns fqdn such as test.no-ip.org and then have

email1@test.no-ip.org

email2@test.no-ip.org

etc etc. tahnk u

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Posted

I'm sure all you get is a DNS address resolved to an IP with any Dynamic DNS service.

The only way I can think is to have an alias such as mx0.example.com which is a CNAME of test.no-ip.org. mx0.example.com will then need to be a record itself. I guess you could also just have test.no-ip.org as your only MX record.

My first thought though would be to test the possibility of receiving and sending on port 25. I would have thought most domestic ISP's will block this communication.

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Posted

SK[' timestamp=1343722926' post='595047579]

I'm sure all you get is a DNS address resolved to an IP with any Dynamic DNS service.

The only way I can think is to have an alias such as mx0.example.com which is a CNAME of test.no-ip.org.

My first thought though would be to test the possibility of receiving on port 25 and sending. I would have thought most domestic ISP's will block this communication.

well i think there was also a way around this for using a ddns fqdn as a web server from your home rite? i imagine there is something also like this for stmp (port 25, like you comment)

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Posted

Can't think of a way as every other SMTP server in the world will be expecting to speak to your server on port 25. If your ISP block it then your pretty much stuffed. DynDNS offer some sort of mail feature though.

As I said test the connectivity first before implementing a solution that won't work. I host my three sites on my home network with the same Dynamic IP being used as an alias. It works fine. I know though that port 25 is blocked outbound as there is no mail functionality working. Kinda annoying as I run forums. Still, they are dead ones these days and are only really used for reference.

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Posted

SK[' timestamp=1343722926' post='595047579]

I'm sure all you get is a DNS address resolved to an IP with any Dynamic DNS service.

The only way I can think is to have an alias such as mx0.example.com which is a CNAME of test.no-ip.org. mx0.example.com will then need to be a record itself. I guess you could also just have test.no-ip.org as your only MX record.

My first thought though would be to test the possibility of receiving and sending on port 25. I would have thought most domestic ISP's will block this communication.

Not all do. Time Warner for example leaves the port open but adds its residential IP blocks to one or more DNS Block lists, so that all mail that comes from them gets marked as spam by receivers who check against said lists.

I'd imagine using something like DDNS probably would cause a similar issue. Though idk.

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Posted

Not all do.

Which is why I said test.

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Posted

i mentioned that with noip i can host a web server on port 80 even if my isp blocks port 80. so i imagine there is something similar for port 25 rite?

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Posted

if they can do that then sure. A quick browse of no-ip shows also...

Alternate-port SMTP

Can't send out email? Alternate-Port SMTP is for administrators that have an ISP that blocks outbound port 25 or road warriors that don't want to change their smtp settings every place they go.

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Posted

possible yes, but you will be black listed before you even say go. DHCP'd isp addresses are already blacklisted in spam databases.

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Posted

possible yes, but you will be black listed before you even say go. DHCP'd isp addresses are already blacklisted in spam databases.

I wish I was blacklisted from spam bots :(

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Posted

I know...it is a battle that IT has been fighting for a long time. And it is getting worse.

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Posted

If what you want to do is accept incoming mail, yeah not too many issues there - get a MX record pointed to where you want to accept mail. That is about it.

Where the problem comes in is sending, as mentioned already -- most of the major players will block you from sending them email from a dynamic IP. Even if not using a block list, do you have a valid PTR for this IP - not going to accept mail from you.

So if what you want to do is send mail to your friend billy on his HOME smtp server, then sure go for it. If what you want to do is send actual production email that your sure is going to get there. Not so much, not to any of the major player domains, or any companies doing any sort of decent filtering.

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Posted

I run my own exchange server. Receiving emails are OK but sending gives an error. Tested via Exchange Connectivity and its says that no PTR Record available for the IP. Any solution to this?

by the way, I use Zerigo as my Dynamic DNS.

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Posted

You can use a smart host for outbound smtp "http://dyn.com/email/dyn-standard-smtp/"

I saw it already. Probably, my last option would be that. Isn't there any free option available?

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Posted

receiving you will be fine, it is always the sending. Many isps have closed out bound port 25 traffic outside of their network when on their dynamic ip network. Many spam filters have excluded dynamic range from being able to get through. How do you get around the world denying you?

The option would be to send through a mail host, you can use your isp mail host, but they may have a sending limit.

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Posted

receiving you will be fine, it is always the sending. Many isps have closed out bound port 25 traffic outside of their network when on their dynamic ip network. Many spam filters have excluded dynamic range from being able to get through. How do you get around the world denying you?

The option would be to send through a mail host, you can use your isp mail host, but they may have a sending limit.

Using my ISP Mail Host is a great idea. I don't mind if they have sending limit. Do I only require to get the SMTP for the ISP? or what else info is required?

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Posted

yeah sure there are lots of people that provide FREE email servers for you to send your mail through :rolleyes:

If you want/need to send email - then you have to be ready to show your not some random box on the net sending spam. No business that needs to use email is going to be on a dynamic IP. Your also going to be able to setup a PTR because again your not a on dynamic IP and your ISP provides you the ability to change the name the IP resolves too. Only the owning ISP can do this, arin controls who where netblocks point for dns here in the US, other parts of the world would be other orgs, lacnic, ripe, apnic, afrinic

Shoot more and more companies are giving up on running their own mail and doing it in the cloud themselves - not even running their own email servers any more. Or contract out companies to be the front man to their exchange boxes - where this other network sends and recv the mail, and exchange gets mail from this company, and sends all email through them "smart host"

Here is the thing - running your own email server on a home connection for anything other than a hobby or for you to get mail from to some bs domain that gets a couple of mails a day and sends a few a day through your isp email server is nothing more than an exercise in futility.

More likely than not your prob just going to end up running a spam machine anyway ;)

edit: What version of exchange are you running? Look up how to setup smarthost. Keep in mind that many isp will not allow you to send mail from other than your email address, ie say account is user@isp.tld -- many will not allow you to send mail through their servers that say the email is from billy@otherdomain.tld

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Posted

SMTP you will need as well as your account info to be able to authenticate and send mail through. You will need to send mail as this account though...the mail header needs to show this for your recipients to be able to receive mail. Unless they just do a ip check (which may be the case), but if they do any sort of resolve and the ip doesn't match the header host it won't make it through. There is a lot that goes on to verify authenticity of the sender in a spam filter.

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Posted

edit: What version of exchange are you running? Look up how to setup smarthost. Keep in mind that many isp will not allow you to send mail from other than your email address, ie say account is user@isp.tld -- many will not allow you to send mail through their servers that say the email is from billy@otherdomain.tld

am using Exchange Server 2013 over Windows server 2008 R2 (which is a DC as well). My ISP is Saudi Net (worst ISP in the entire middle east with no support at all). Cant even request for PTR. Tried the SMTP for them but still not working, maybe am not configuring Exchange Server properly.

SMTP you will need as well as your account info to be able to authenticate and send mail through. You will need to send mail as this account though...the mail header needs to show this for your recipients to be able to receive mail. Unless they just do a ip check (which may be the case), but if they do any sort of resolve and the ip doesn't match the header host it won't make it through. There is a lot that goes on to verify authenticity of the sender in a spam filter.

I tried tons of ways but none work. Web Server was way easy configuring compared to exchange server :/

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Posted

"Cant even request for PTR."

I don't know of any ISP that would setup PTR of a dynamic IP other than the generic ones you get.. For example

;; QUESTION SECTION:

;xx.xx.13.24.in-addr.arpa. IN PTR

;; ANSWER SECTION:

xx.xx.13.24.in-addr.arpa. 7200 IN PTR c-24-13-xx-xx.hsd1.il.comcast.net.

Now such a PTR might meet some filtering some domains do in the sense that it exists.. Others might reject it because its not a true reflection of the forward name.. So for example if your mail server IP is resolved via smtp.somedomain.tld, they might like the PTR of the IP that resolves to to reflect the same smtp.somedomain.tld

As I already mentioned, some ISPs won't allow their smtp servers to send mail for anything other than the account holder email address. So if your email address with your isp is umaki@isp.com and your trying to send email from umaki@otherdomain.tld - even if you auth with your specific account info, their server might tell you to get lost since the email address is not valid for that account.

Many ISPs don't even allow outbound on 25 from their dynamic client networks, nor allow their smtp server to send email for any other email address then what is listed on the specific account - this is to help reduce spam being sent from their network. If you have such restrictions then your only solution is to pay for a smarthost that allows you to send mail they forward on your behalf on a different port, etc. The dyndns company already mentioned provides such solutions. If you not willing to pay for such services - how are you affording exchange? ;)

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Posted

If you not willing to pay for such services - how are you affording exchange? ;)

I can afford all the services, but I wanted to setup it for free at all. By the way, setting up all this was a part of my exercise. Wanted to learn about the Web hosting, Domain Controller, Email exchange. All was setup properly except this Exchange. I tried adding the PTR host in Zerigo (my Dynamic DNS service) it was done but my ISP really need to assign me a PTR record to my IP (which seems not possible for Dynamic IP Users). How about if I search for some free SmartHost providers before paying for something :rofl:

Edit: by the way, I get free license for Microsoft Products :D so trying all of them is not that bad :rolleyes:

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Posted

Your not going to find a FREE smart host.. Not that I can think of - I don't even think google apps when it was free for your domains allowed that?

What would the smarthost get out of it? Other than prob blacklisted because you were using them to send spam ;)

You can study the setup of exchange without really having to send mail to all the major players.. Does your isp allow outbound of their network on 25? Simple enough to test, try connecting to a smtp server somewhere?

Cheap way you could do it is get yourself a VPS somewhere... I have a vps for $15 a year that would be more than capable of sending email for me, etc. And I can setup the PTR on the IP the host gave me. So it can be done for very cheap.

But again if all your doing is playing/learning does not matter if the major players will block you.. there are plenty of domains you can send to for testing that wont filter you.

So telnet to a smtp server on 25, can you connect - if so then your isp allows you to send outbound on 25 and could setup exchange to directly send.. Just some of the major players are not going to accept mail from you.

budman@ubuntu:~$ telnet mailin-01.mx.aol.com 25

Trying 205.188.159.42...

Connected to mailin-01.mx.aol.com.

Escape character is '^]'.

554- (RTR:DU) http://postmaster.info.aol.com/errors/554rtrdu.html

554 Connecting IP: 24.13.xx.xx

Connection closed by foreign host.

so you see my ISP allows me outbound on 25, but mail server for AOL told me to get lost ;) Because

54 RTR:DU

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Posted

Cheap way you could do it is get yourself a VPS somewhere... I have a vps for $15 a year that would be more than capable of sending email for me, etc. And I can setup the PTR on the IP the host gave me. So it can be done for very cheap.

Where? can I get that too?

Will post the telnet results once I get the exact SMTP for the ISP :wacko:

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Posted

smtp for the isp? Just do a dns look for any smtp server for any domain. Use aol for an example

As to a vps -- here are some listings of cheap ones

http://www.lowendbox.com/

http://lowendstock.com/

Mine is with http://buyvm.net/

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