E-mail not getting to valid address...why?

[troverman]

One of our salespeople routinely receives e-mail messages from a certain customer, but cannot reply or send new messages to this address. We use Exchange 2003, and I see the messages he sends or replies to just sit in the queue until they eventually time out and a NDR is sent back. I have tried from my exchange work address and the same thing happens. However, I sent this customer a message via g-mail which he received no problem.

Any ideas? If the customer's junk filter is catching our messages, would they sit in our queue retrying until they time out?

[jlego]

what does the NDR say?

[troverman]

Error 4.4.7 - the message expired.

[jlego]

did you try to manually connect to the remote smtp server from your server using telnet on port 25?

telnet remote-email-server 25
helo
mail from: [e-mail]
rcpt to: [e-mail]

let me know what the response says

[troverman]

"Sender OK"
"Recipient OK"

[jlego]

what do you have setup for your send connector?

[jlego]

also - just to verify goto www.mxtoolbox.com type in your external ip for your mail server, make sure you are not black listed anywhere.

do you have a smart host configured on the send connector?

[troverman]

Looked in the routing group and there are no conenctors.

Not blacklisted based on the above link.

Thanks

[jlego]

well you are going to need to configure a send connector.

[jlego]

your going to want to do customer

smtp
address space *
cost 1
its up to you to include subdomains

use domain name system mx records to route mail but i would suggest that you get a smart host.

check with your isp - they may let you use there corporate mail server (mail.isp.com) as a smart host - youll have to talk to them however. I think macafee lets you use there mail servers as smart hosts too.

[jlego]

you are going to want to do custom*

[troverman]

In two years of operation with this server setup we haven't needed one until now? Is that odd?

[troverman]

Sorry, can you explain why we have gotten along without one for a couple of years?

[jlego]

im just offering a suggestion. everyone i have delt with told me that i need a send connector - every book, video tutorial, and course if taken says to use send connector. i'm actually kind of surprised that you didnt have one...

on the hub transport you have receive connectors and send connectors
receive connectors receive your new email based on the mx records of your domain and so on

send connectors tell the server have to route mail to the outside world

try to send an email that you know will get held in the que
go to toolbox - que viewer. let me know where it says the message is stuck at

[jlego]

tell the sever how to route mail to the outside world * sorry my typing is off this morning

[jlego]

OH im sorry i back tracked and saw that you are using exchange 2003. I'm speaking of 07-10

[jlego]

you are right - in exchange 03 send connectors are read only you dont need to configure one until you migrate

or something like that

[troverman]

Are you saying now I don't need to do anything, or do I still need a SMTP connector?

BTW, we also use Postini as our mail filter. But no outbound filtering is set.

[jlego]

I'm sorry let me slow down --

on exchange 2003 you dont need to configure a smtp send connector - you only need to do this on exchange 2007 +, so you don't need to configure one. I am sorry about that I was thinking you where on exchange 2007..

Just so I understand, you are using postini as a incoming mail scrubber for spam/antivirus etc? and there is no filtering on outbound email correct?

[troverman]

That would be correct on Postini.

[jlego]

Ok i reread your original post. if the message was delivered to there junk email - no you would not see it in the Que.

have you ever been able to send email to these outside addresses ?

[troverman]

There is only one e-mail address in question. I think years ago sending mail to this address worked (hard to get a straight answer out of sales). However about 2 years ago we swtiched from individual servers to virtualization and i am not the one who set up exchange...i'm guessing it had something to do with that but hard to say.

[jlego]

do you mind giving me your mails server external address? if not thats fine.

you are going to want to verify a few thing..

make sure that you have PTR records (reverse dns) with your ISP for your mail server.
you can test this by doing ptr:mailserverexternal on mxtoolbox.com

do you know if you have SPF records - sendID setup?

my guess is this,
that remote mail server is doing checks on the email. spf , reverse dns, and so on. but it is finding things it does not look and considering your mail to be 'spoofed' and not accepting it.

[troverman]

(taken down for security)

[jlego]

im not 100% familiar with exchange, it has been along time since i used it. my suggestion would be to configure a smart host (verify easy to configure based on google searches) that has all the correct ptr, rdns, spf, sendierid, and so on information configured. this way when the remote mail server sees the email everything looks good and it is delivered.

i actually posted a mail server check list before. let me see if i can find it and i will post it - that is if you want to try and configure everything properly on your end

[jlego]

i keep typing the wrong shit. im not 100% familiar with exchange 2003*

[troverman]

yeah that would be good, if you don't mind

[jlego]

Mcafee Mxlogic 'cloud' anti-spam functionality for incoming message.

Antivirus on each computer in company

Antivirus on Exchange and DNS servers

Setup SPF record

Setup DKIM

Setup domainkey

Setup senderID

Submit SPF to Microsoft, Yahoo, etc. for 'whitelist' purposes.

Configure size limits for messages in Exchange to safe numbers

I have 2 outside IPs for my email server, in case one gets blacklisted, switch to the backup.

My Internet site rests on a different ip than the mail server

All mass emails for company sent through 3rd party company (listtrak.com)

Setup domain alias, media, enews, and bounce for the 3rd party mass mail software.

Verify the setup using [e-mail]

Configure group policy and our opendns.org account to prevent unwanted actions and website viewing

Configure rDNS for all sending server's IP address(es) (Not needed inbound servers.) port25 will catch this.

Configure subdomain for outside mailers to use, or have them use their addresses.

Match hosts DNS to servers name used for HELO/EHLO message. Switch name if switching IPs.

Setup mechanism for clearing invalid addresses off mass mailing list.

Register your server with dnswl.org.

[jlego]

send an email to the [e-mail] and post the response if you could - i forgot about that

[troverman]

thanks jeff, appreciate the help. i'll work my way through this list.