Ideas for solving SMTP problem at work

[Sideswipe001]

Scenario:

The place I work is a small buisess (about 40 employees). Our server is an Exchange 2000 server at work, where all the "in-office" workers are directly connected through outlook. We have a few laptop users who only use their laptop, even while in the office.

Right now, all the laptop users are set to get their e-mail by POPing our server, and using it as their SMTP server for outgoing mail as well. It works without any problems most of the time.

Laptop users who go out on the road are forced to use a dial up ISP (Juno usually) if their hotel doesn't have high speed internet. Some of them also use their laptops on home networks (DSL or cable modem) when they go home at nights.

The problem:

Some ISPs block out use of all SMTP servers except their own. When the laptop users dial in over Juno, they have to manually go into their settings in Outlook and change the SMTP server to "smtp.juno.com" or they can no longer send out e-mail. They can recieve it fine. The same users, if they go home, have to change the SMTP settings AGAIN to their ISP's SMTP server. Then when they come back to the office here, they change their SMTP settings to use our server again. When they are at a hotel with high speed internet, they can use our SMTP server without any issues.

What I'm looking for:

Is there a way to set it up so that the users won't have to constantly shift their SMTP settings, depending on who's network they are logged into? The ISP won't relay any messages that don't originate from inside their network, and won't allow any other SMTP servers to be used while inside of it. I need a way to set this up so that they won't have to keep changing settings.

NOTE:
OWA is not an option. Tried it before, they all complain about how they like the functionality of Outlook better.

 

[Kilrsat]

1) Set your exchange server to also listen on an alternate port

or

2) Setup a VPN, so your employees become part of your local network, even from the road.

 

[bsobel]

As Kilrsat said, the right solution is to setup a VPN so these people are on your network remotely. Short of than, you can setup an alternate SMTP server (or even just a port relay) on say port 26. Have your users (the mobile ones) configure outlook to use that.

Bill

 

[mboy]

You can also create an account in outlook and assign the juno SMTP server to that, create a bogus incoming server, have outlook only send for that account (set up the account with the same name,email addy etc as their main account).
When they have to dial up, they can choose the juno smtp account before they send the message off.
I had to set it up for my remote users as we pop our email off our ISP's email server.

 

[netsysadmin]

Another solution would be to upgrade to Exchange 2003 and use OWA which is almost exactly like Outlook 2003. The other one would be to still upgrade to Exchange 2003 and use RPC over HTTP access for the remote users. Essentially that will give access as if they were in the home office without using a VPN setup.

John

 

[martind1]

I didn't think that this was a relay problem since you are connecting directly to your mta. Is yoru mta, acceessable from the internet? or is it local, or behind a firewall?

have them try a telnet smtp.yourhost.com 25. they should be able to get into it.

Look for a new ISP. Obviously they are not satisfying yoru business needs.

 

[bsobel]

Originally posted by: martind1
I didn't think that this was a relay problem since you are connecting directly to your mta. Is yoru mta, acceessable from the internet? or is it local, or behind a firewall? have them try a telnet smtp.yourhost.com 25. they should be able to get into it. Look for a new ISP. Obviously they are not satisfying yoru business needs.

Did you even read the post before responding? Plenety of ISP's block port 25 from leaving their networks (Earthlink, Juno, etc). He's trying to deal with that...

 

[classy]

Originally posted by: netsysadmin
Another solution would be to upgrade to Exchange 2003 and use OWA which is almost exactly like Outlook 2003. The other one would be to still upgrade to Exchange 2003 and use RPC over HTTP access for the remote users. Essentially that will give access as if they were in the home office without using a VPN setup.

John

Yep OWA, Exchange 2003. And it wouldn't be that expensive for such a small group.

 

[martind1]

ok, but that is the thing. i dont think that is the problem.

that would be the problem if the laptops were runnign a smtp server, and the mail was originating from that smtp server. I believe THAT is what ISPs block.


So, yes I did read the message. did you read my answer?

 

[classy]

Originally posted by: Sideswipe001
Scenario:


NOTE:
OWA is not an option. Tried it before, they all complain about how they like the functionality of Outlook better.

Well you didn't use 2003, cause its just like Outlook 2003.

 

[bsobel]

Originally posted by: martind1
ok, but that is the thing. i dont think that is the problem. that would be the problem if the laptops were runnign a smtp server, and the mail was originating from that smtp server. I believe THAT is what ISPs block. So, yes I did read the message. did you read my answer?

I'm afraid that's wrong. There is no difference to the network if it's a local SMTP server sending out the mail, or if it's Outlook's SMTP transport. Both need to open port 25 to the remote smtp server, and both are blocked since port 25 is blocked.

Bill

 

[Sideswipe001]

ISPs block out port 25 no matter what kind of computer it originates from. I've had this problem at home. And we use Juno for the fact that it's cheap. We used to use a more "buisness" oriented ISP for it (ITC Deltacom, who we get our T1 access from) but they were charging over $100 a month for the dial in service (plus usage).

Trust me, I would love to convince them to upgrade to 2003 server and/or Exchange 2003. But it goes back to the $$$ issue. Convincing the bosses it's worth it. I was trying to see if there was a "free" way to do it first. I might set up the VPN.

And yes, our server is local and accessable from the internet (on a few ports: 110, 25, 21, and 80). It's running Small Buisness Server 2000 and is a "does it all" server for us.

 

[martind1]

are you sure this server can handle smtp connections from the internet? evenfrom other sources than juno (which i still dont believe is the problem)

 

[Sideswipe001]

Originally posted by: martind1
are you sure this server can handle smtp connections from the internet? evenfrom other sources than juno (which i still dont believe is the problem)

Since all incoming e-mail arrives on port 25, yep, I'm pretty dang sure it does. And like I said, it's not isolated to Juno. If they go home and hook up to their DSL (Comcast I think) or I go home and hook up to my Cable modem (Knology) it's the same thing. At home, I MUST have smtp.knology.net (I called their tech support about this) and the other employee MUST have smtp.comcast.net to send out e-mails. But, at a hotel with high speed internet (and no SMTP limits) everyone can send out through our server just fine.

 

[martind1]

what do they use for a smtp host while in the office?

 

[bsobel]

Originally posted by: martind1
are you sure this server can handle smtp connections from the internet? evenfrom other sources than juno (which i still dont believe is the problem)

Ok, now your starting to get annoying. You obviously don't understand the question nor how email works. Please stop asking the same questions over and over again, your not being helpfull.

YES his sever is accessible from the internet, just not from end user machines where the end users ISP has blocked port 25. Sheesh

Bill

 

[martind1]

sorry bsobel. i didn't mean to offend someone who apparently is just looking to start fights. excuse me for tryign to find out more information. I guess trying to be helpful is just plain offensive. Since this isnt your thread, maybe you should just stop reading it.



I guess I am just a silly guy though.

 

[bsobel]

Originally posted by: martind1
sorry bsobel. i didn't mean to offend someone who apparently is just looking to start fights. excuse me for tryign to find out more information. I guess trying to be helpful is just plain offensive. Since this isnt your thread, maybe you should just stop reading it. I guess I am just a silly guy though.

The six other responders where able to understand the question and respond accordingly. If you can't, don't.

 

[martind1]

so I guess my answer of switch ISP, is jsut nonsense too? since it is the easiest solution, I proposed it. Then the conversation went on.

so I moved on and tried to figure other things out. Perhaps it is you who does nto understand.

 

[bsobel]

Originally posted by: martind1
so I guess my answer of switch ISP, is jsut nonsense too? since it is the easiest solution, I proposed it. Then the conversation went on. so I moved on and tried to figure other things out. Perhaps it is you who does nto understand.

No, the suggestion to change ISP was a reasonable one, but the OP already responded to that. The OP orignally stated they are using Juno because it's cheap (and most ISP block port 25 anyhow from dialup accounts, those that don't today will shortly).

As for understanding, you showed the thread you don't understand the technical issue with the "that would be the problem if the laptops were runnign a smtp server, and the mail was originating from that smtp server. I believe THAT is what ISPs block." comment. I and the other people actually trying to help in this thread understand the problem perfectly as we deal with it ourselves. Perhaps you should re-read the thread and note the number of times you have been corrected other posters. There are plenty of technical solutions to this problem, let the OP sort thru the suggestions and work this out.

That said, if you want to carry this on, just PM me. We shouldn't completely hijack the OP thread

 

[martind1]

That said, if you want to carry this on, just PM me. We shouldn't completely hijack the OP thread

exactly what my next post was. to far off track.

 

[bsobel]

Do you have a firewall in front of the mail machine? If so, can it be configured to port forward another port to 25 (back to the use port 26 or 2626 or some random port# question). If not, there are a number of apps that will run on the box and provide relay (WinIpRelay, Ip*Works Secure Tunnel, etc). Most of those don't scale to lots of users, but for a small office they would be fine.

Bill

 

[Sideswipe001]

Originally posted by: bsobel
Do you have a firewall in front of the mail machine? If so, can it be configured to port forward another port to 25 (back to the use port 26 or 2626 or some random port# question). If not, there are a number of apps that will run on the box and provide relay (WinIpRelay, Ip*Works Secure Tunnel, etc). Most of those don't scale to lots of users, but for a small office they would be fine.

Bill

We don't currently, but that's an interesting idea. Right now we just have a router NATing and port forwarding 21,25,80,and 110. I hadn't thought of forwarding another port to 25. Interesting thought.

 

[martind1]

wont this not work becasue it needs to be port 25 to accept mail?

and isnt that not the problem at hand? aren't most of the email programs unable to switch what port to contact the smtp server on?

 

[bsobel]

Originally posted by: martind1 wont this not work becasue it needs to be port 25 to accept mail? and isnt that not the problem at hand?

UGH. As the OP understood, you forward BOTH ports to the actual internal mail server on port 25. Then, other smtp servers contact you normally on 25 while you configure your clients to use the altnerate port (say 26). When roaming, port 26 won't be blocked and his users can send mail (and the ISP is still safe from zombies trying to find open relays on 25)

aren't most of the email programs unable to switch what port to contact the smtp server on?

Almost all if not all modern mail clients (including what he uses, Outlook) can change the SMTP port to whatever you like.

Bill