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HubTechnicalFlag for Afghanistan

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question about changing ISPs and Email

Hi Guys:

Internally, I've got Tru64 running Sendmail.  

We are changing ISPs, and I want to upgrade to Exchange 2003.  If I am understanding this correctly, I simply need to contact my new ISP, and have them take over email for my organization.  Is this correct?  Then, I can just use the Exchange Box?
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PsiCop
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Note that the version of sendmail shipped by most vendors is usually horribly outdated. I doubt HP is any exception. You should check the version (telnet to port 25 on the machine, look at the banner for something like 8.XX.YY where XX and YY are numbers) anything less than v8.12.10 is outdated. Visit http://www.sendmail.org to get newer code (8.13.1 is the latest, 8.12.10 is generally considered the oldest that is OK to run).

Exchange is NOT an upgrade from sendmail - its a very expensive downgrade. If you plan on making your organization instantly vulnerable to every bit of malware on the 'Net, I'd suggest you KEEP your sendmail installation and turn it into a relay that will protect Exchange (hint: this is what Microsoft does - or did for a long time - with their corporate E-mail system). Run some open software like MIMEDefang (http://www.mimedefang.org/), SpamAssassin (http://spamassassin.apache.org) and Clam-AV (http://clamav.net/) to filter the spam, delete the dangerous attachments, and virus-scan whatever gets thru.
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I'm not very proficient in Unix, so thought it made more sense to upgrade to Exchange, no?
Its not an upgrade, no matter how you look at it.

Getting proficient with UNIX will cost your organization a lot less downtime, lost productivity and money than it'll lose with every new iteration of NetSky, Sasser, Slammer, PhatBot, et. al. ad. nauseum. You have a UNIX platform, you have a working sendmail - if nothing else, leverage that existing investment by interposing it between the 'Net and the vulnerable Windoze environment.
I don't suppose there would be a graphical UI for the install, is there?
Nope. Ya gotta actually understand what is going on.
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vand

Hi Hub Technical,

How your mail is hosted is determined by you MX records, not necessarily your ISP.  If you are running Exchange, and you are on your own network ( not on a sub LAN of some organization ) That is, you have a static WAN address, a router and the capability to modify forwarding, you should have your domains MX records point to the external IP and enable forwarding on the router.  If your ISP is hosting your domain name (an unnecessary expense) then they will have to be notified to forward the MX records to ensure that all mail for your domain is received.

It typically takes 3 Business days for all DNS servers to be notified of your record change.

There are allot of variables that go into this, so I'll need more info as to how your domain is hosted in order to better answer this.  Setting up exchange is pretty straight forward, as is changing you MX and name servers, but, it can be pretty "involved".

Hope this helps
To answer your question instead of bashing MS:
Yes, your ISP should be able to take over email for your organization assuming they handle your DNS information.
Assuming you have a public domain such as yourcompany.com, you will need to have them update you MX (Mail exchange) record in DNS to point to the IP address of your new Exchange 2k3 server.
Do I have my ISP point my MX records to my new router?  I've got a Cisco PIX with a static WAN IP and behind that a SonicWall Firewall.  Should I put the mail server on the DMZ of the firewall, or just as part of our LAN?  Couldn't I just point the MX records to my SonicWall?  :confused:

Background, we were sharing an internet connection with another organization, but we now have our own dedicated T1, and are setting up an entirely new network.  We host our own webserver inhouse www.xyz.com and are running sendmail for email.  
If you are hosting your own webserver than you should have access to modify your WX and MX records. With a dedicated T1, have the MX records point to the static WAN IP and forward ports 25 and 110 to the internal IP of the exchange server.  I would also recommend giving a "friendly" name to the MX such as mail.xyz.com
Verify what /who name servers your domain uses. Just change the MX record of your domain to a Public IP assigned to you by your ISP.  In your Sonicwall  Firewall, Go to Advanced and set up a 1 to 1 NAT.  your Public IP to your private IP. Now in your Rules, Add a rule for SMTP 25 allow to your Private IP and any other Rule you wish.

If your ISP only assigned you 1 IP,  you may want to request for more.  They may ask you to justity your request to ARIN.

Good Luck
A quick note,  

Once you have determined where your authoritive name servers are, have them change the TTLs for your DNS records to 15 minutes a few days before your change.  This will allow your dns changes to propagate faster.  You can go lower but rumor had it that AOL doesnt honor lower ttls than 15 mins.

Cheers!

Dan
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vand

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