Client change email port to 2525, now we can't send to them....How can we now?

Hi,

We have a small client who uses an ISP for their email services.  One day they decided to change the mail port from 25 to 2525 to try to stop spam.  Well, since they've done this many folks (Us included) have been unable to send to them.  We just figured this out by chance and then called the client to verify.  Telnetting to port 25 of the server yields nothing now since their ISP is now blocking that.  Now, the question is how can I configure our Exchange 2003 server to send email to this particular domain over port 2525 without causing issues with the thousands of others we send to?

TIA

Al
LVL 1
alchikAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

LeeDerbyshireCommented:
You can change the port number in Exchange System Manager by looking at the properties of the Default SMTP Virtual Server, and clicking the Advanced button.  That will allow you to send to this one client, but when everyone else is using port 25, you won't be able to send to anyone else.  The rest of the world assumes that SMTP servers listen on port 25 - they can't keep trying every port to discover the changed port number.  If they can't connect on port 25 they will just give up.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
SembeeCommented:
The client needs to change their port back to 25. They cannot expect everyone who emails them to use another port. Asking Hotmail, AOL or any other major ISP to comply will be met with a polite no at best and a laugh at worst.

You cannot deal with spam by simply changing the port.

Simon.
0
alchikAuthor Commented:
The client has no control over the ISP changing the port unfortunately.  After doing some googling it seems others are doing this as well.  I was sort of hoping there was a way of routing domain specific traffic to say, a specific connector/virtual server what would send out via 2525.  
They say there are receiving email from some people.  I can send to them from gmail and yahoo.
0
Problems using Powershell and Active Directory?

Managing Active Directory does not always have to be complicated.  If you are spending more time trying instead of doing, then it's time to look at something else. For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why

SembeeCommented:
I cannot believe that the ISP is expecting this to be a public facing port. As Lee has stated above - the entire SMTP system is based on the port 25. Like http is port 80, https is 443 and POP3 is 110.
This sounds like either a massive cock up by the ISP or someone has taken the private port (for client to ISP communication) and is treating it as the public facing port.

Simon.
0
alchikAuthor Commented:
I agree with you Sembee.  I've emailed their ISP support group directly (funny, their mail server works just fine...) to see if I can get an answer.  The client has tried to get an answer from them but the ISP claims it's everyone else's fault.  It's bizarre but seems it's not an isolated incident.  Dyndns.com offers MailHop to get around such things.  Odd....
0
SembeeCommented:
The service that dyndns.com is offering is a private service. You send your email to them and then they send it on to the internet using the conventional ports. I suspect this is a similar service.

Simon.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Exchange

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.