MS Exchange experts out there?

[mrgreen4242]

Any of you guys MS Exchange experts? I'm a complete newb when it comes to Exchange, but I am setting up a server for my smallish non-profit employer. We happened to have a license for 5.5 from a BackOffice purchase (we needed SQL Server way back then and got this whole thing), and so here I am.

I have the server all set up, we are using the calendaring features right now, everyone is able to connect to the server. I am getting ready to set it up as an email server as well, and have our MX record transfered to our local server (connected to a fractional T1 line - bandwidth is enough and downtime not an issue).

I've read the books, looked at the wizards and it looks like I just need to setup the ICS and then have our MX record moved... But since I am going to be moving a bunch of exisiting email address over I can't make any mistakes.

The ICS wizard talks about setting up the DNS records and whatnot BEFORE you run the wizard... this is the part that I am stuck at... it doesn't make sense. I'd want the Exchange server ready to take mail over SMTP before I moved any DNS entries to it, so no email gets lost or bounced.

If I set up the ICS connector first and then change the MX record to point at our server will I cause any problems?

Thanks for any help,
Rob

 

[balamw]

I'd want the Exchange server ready to take mail over SMTP before I moved any DNS entries to it, so no email gets lost or bounced.

Ah 5.5, how quaint. [2K and 2K3 are much more pleasant in terms of their SMTP handling].

The way I've usually handled this is using secondary MX entries or multiple equal priorit MX entries. I presume you will have a way of retreiving mail from the server that is currently handling the mail, right?

B

 

[mrgreen4242]

Ah 5.5, how quaint. [2K and 2K3 are much more pleasant in terms of their SMTP handling].

The way I've usually handled this is using secondary MX entries or multiple equal priorit MX entries. I presume you will have a way of retreiving mail from the server that is currently handling the mail, right?

B

Hehe, ya 5.5... we're a non-profit, so we're always short on fund. We do have access to the current email server, it's from our (soon to be former) ISP.

I'm moving the website to a new host (used to be with our ISP as well), and at the same time changing the mail to our Exchange server. If there is a secondary MX record will it send it to both servers? That'd be perfect, as I could test the Exchange setup before completely killing off the old server...

Thanks for your help! Hope I don't sound like a dolt... I'm primarily a database admin...

 

[balamw]

If there is a secondary MX record will it send it to both servers? That'd be perfect, as I could test the Exchange setup before completely killing off the old server...

Unfortunately, no. Mail will be sent to the highest priority (lowest number) MX server found in the DNS that is available. If you're trying out a new server you could set it for a higher priority (lower number) than your current server, so that when it's online all mail goes to it, but if it is unavailable e-mail will still be delivered to the next priority MX. If they have equal priority they will usually share the traffic.

Is the Exchange box behind a hardware firewall? (I hope so!)

If so, here's a way you could potentially test it all out and still set up all the DNS beforehand.

1) Disable port forwarding of SMTP traffic (port 25) to the Exchange box
2) Make the DNS changes to make the new Exchange box your highest priority MX server (typically the MX priority will default at 10, make the new server 5).
3) Run the wizard, to enable SMTP.
4) Test out the SMTP manually by using telnet *
5) Open the hardware firewall's port forwarding to traffic, and watch your queues from behind the firewall.
6) After you're satisfied that works, eliminate the old MX record
7) Retreive any e-mail collected at the old server using the current method
8) Reset the MX priority of your new server to 10.

EDIT: Wait. Did you say ICS? As in Internet Connecion Sharing? I read IMC Internet Mail Connector (formerly known as IMS Internet Mail Service). Are you actually using a Windows box to share your internet connection instead of a $50 hardware router? Even a non-profit should be able to afford one of those or even have an old box around they could run smoothwall on.

B

 

[mrgreen4242]

Unfortunately, no. Mail will be sent to the highest priority (lowest number) MX server found in the DNS that is available. If you're trying out a new server you could set it for a higher priority (lower number) than your current server, so that when it's online all mail goes to it, but if it is unavailable e-mail will still be delivered to the next priority MX. If they have equal priority they will usually share the traffic.

Is the Exchange box behind a hardware firewall? (I hope so!)

If so, here's a way you could potentially test it all out and still set up all the DNS beforehand.

1) Disable port forwarding of SMTP traffic (port 25) to the Exchange box
2) Make the DNS changes to make the new Exchange box your highest priority MX server (typically the MX priority will default at 10, make the new server 5).
3) Run the wizard, to enable SMTP.
4) Test out the SMTP manually by using telnet *
5) Open the hardware firewall's port forwarding to traffic, and watch your queues from behind the firewall.
6) After you're satisfied that works, eliminate the old MX record
7) Retreive any e-mail collected at the old server using the current method
8) Reset the MX priority of your new server to 10.

EDIT: Wait. Did you say ICS? As in Internet Connecion Sharing? I read IMC Internet Mail Connector (formerly known as IMS Internet Mail Service). Are you actually using a Windows box to share your internet connection instead of a $50 hardware router? Even a non-profit should be able to afford one of those or even have an old box around they could run smoothwall on.

B

Hehe, yes, it's behind a hardware firewall. No, we are not using ICS... I just had a brain fart with the acronym... The manuals mention that the IMC used to be called IMS and so I added the two together in my head and got ICS.

Thanks for the tips. Sounds like a good plan... do MX records take as long as other DNS entries to update (up to 12 hours) or is somehow magically faster?

 

[balamw]

Hehe, yes, it's behind a hardware firewall. No, we are not using ICS... I just had a brain fart with the acronym... The manuals mention that the IMC used to be called IMS and so I added the two together in my head and got ICS.

Thanks for the tips. Sounds like a good plan... do MX records take as long as other DNS entries to update (up to 12 hours) or is somehow magically faster?

Phew. You scared me!

Yeah, the DNS takes a while to propagate, but as long as you don't try #6 too early you should be fine in doing everything without waiting. Since your DNS is the one being changed, changes behind your firewall should be instantaneous, and all you have to be concerned about is catching the e-mail sent by stragglers who might have the old MX record cached for 12 hours, or the spammers who think that sending mail to a secondary MX gets them in more easily.

It's probably a good idea to collect the e-mail from the old server again another 12-24 hours after you finally remove its MX record.

B

 

[mrgreen4242]

Since your DNS is the one being changed, changes behind your firewall should be instantaneous, and all you have to be concerned about is catching the e-mail sent by stragglers who might have the old MX record cached for 12 hours, or the spammers who think that sending mail to a secondary MX gets them in more easily.

Er, don't I have to change the MX record with the registrar? If I JUST change it on our servers DNS table will it "overwrite" what the official domain registry list as being the MX server?

That probably seems like a stupid question, but like I said - DB guy...

 

[balamw]

Er, don't I have to change the MX record with the registrar? If I JUST change it on our servers DNS table will it "overwrite" what the official domain registry list as being the MX server?

That probably seems like a stupid question, but like I said - DB guy...

DNS is just a very funny distributed DB. There's a reason they call 'em host tables

What I meant is that your local DNS servers should already be dealing directly with your registrar for public IP address lookups, so when it looks up an MX record it should be doing so directly from your registrar.

I've worked this two ways. local addresses are in a subdomain e.g. site.company.com and public addresses lose the site part, or to have the local domain be company.com just like the public IP addresses, but have it look up any entries it can't find in the registrar's DNS.

B