Internal Emails and External emails??

itdaddy · March 2009

I want to understand something about how email is sent in a LAN environment and an external WAN environment. What I mean is this:
If I a user within a LAN and active directory domain structure send an email to a coworker, how does it get there? via Active directory? I heard the delivery of emails in a active directory environment is different than sending it thru SMTP external WAN addresses? Like servers send it via SMTP but witin the LAN the internal exchange server is a distirbution server that looks in the Active directory users and groups and the active directory sends the emails to its prospective domain contrllers based off OU groups and userrs?? is this true can someone straighten me out?

Thanks

sprkymrk · March 2009

Well, if you mean Exchange specifically, and not just "email" (think about how email would work in an AD environment that does not have an Exchange Server) then, yes, it is a bit different.

See if this helps - I had to use google myself because I really couldn't formulate an answer off the top of my head.

New Transport and Routing Functionality

It's a good question though, Robert. I wonder if any Exchange gurus (royal?) can answer this for us.

HeroPsycho · March 2009

It is the job of the categorizer to determine if the message is destined to an internal or external destination. It does this through an Active Directory lookup.

Managing Queues

It attempts to resolve the address to a user. If it cannot find a match, it uses the configuration of accepted domains, authoritative domains, the SMTP virtual server, relevant send connectors, etc. to route the message appropriately.

blargoe · March 2009

Active Directory itself never handles the actual email. All of the mail transport is handled by the Exchange servers themselves. Exchange and AD are tightly integrated in that it uses the same directory to store all Exchange-related objects and configuration. Also in Exchange 2007, mail flow between Exchange servers uses the same routing as AD Sites. But AD domain controllers never touch the actual email.

HeroPsycho · March 2009

blargoe wrote: »

Also in Exchange 2007, mail flow between Exchange servers uses the same routing as AD Sites.

True, although keep in mind you can specify site link costs that differ for Exchange routing from Active Directory replication routing.

How to Set an Exchange Cost on an Active Directory IP Site Link

itdaddy · April 2009

But AD domain controllers never touch the actual email.

Blargo are you sure about this? I read some where that mail goes from DC to DC I thought..for example.not that this means anything but check this out...we have 4 sites...the exchange 2003 is at the mothership site I call it. We have a hub and spoke topology using T1s. Sometimes emails in MS Outlook 2003 get delayed 2 days. And that usually happens when we have left our servers up for more than 30 days..Our servers for some reason like 21 days or 30 day reboots..and when this happens no delayed emails for many days past the 30 day reboots. And another question. How does the exchange server know where to distribute each email to each user when they open up the MS Outlook 2003 client? You said some sort of transport layer? does this transport mechanism have a port and service name? Cause it surely doesnt use SMTP locally within the LAN does ? I guess I just want a port number and service that relays it to each MS Outlook 2003 client but this has been the case at my work..and of course sometime users are corrupt and we have to redo their email box. Or defrag/maintenance thru manual means via command line defrag and dissmount email stores....that has helped before too even though it says it does a automatic maintenance cycle, I think the manual one does a better job..personal opinion. I just want some service name and port. But
MAPI is when you have MS Outlook 2003 client outside your LAN correct. I guess..I really think it is AD some how transporting emails to each client. Although each client does have the mail server configured it so maybe it is direct sync to each client...Sorry for babbling, so you say it is called what that transport emails to the MS Outlook 2003 clients? and any port?

Thanks for helping out.Just want to know.

Thanks sprkymrk I try..

to you all

rjbarlow · April 2009

I confirm (naturally) that never DCs touch e-mails, they are just looked up by the Exchange servers for the information needed, like the server on which resides the recipient's mailbox. Additional instruments are in place in the Exchange servers like the Link State Table for routing decisions; e-mails routed are destined always towards other mail servers, not necessarily Exchange, because those can be destined out of your organization.

HeroPsycho · April 2009

itdaddy wrote: »

Blargo are you sure about this? I read some where that mail goes from DC to DC I thought..for example.not that this means anything but check this out...we have 4 sites...the exchange 2003 is at the mothership site I call it. We have a hub and spoke topology using T1s. Sometimes emails in MS Outlook 2003 get delayed 2 days. And that usually happens when we have left our servers up for more than 30 days..Our servers for some reason like 21 days or 30 day reboots..and when this happens no delayed emails for many days past the 30 day reboots. And another question. How does the exchange server know where to distribute each email to each user when they open up the MS Outlook 2003 client? You said some sort of transport layer? does this transport mechanism have a port and service name? Cause it surely doesnt use SMTP locally within the LAN does ? I guess I just want a port number and service that relays it to each MS Outlook 2003 client but this has been the case at my work..and of course sometime users are corrupt and we have to redo their email box. Or defrag/maintenance thru manual means via command line defrag and dissmount email stores....that has helped before too even though it says it does a automatic maintenance cycle, I think the manual one does a better job..personal opinion. I just want some service name and port. But
MAPI is when you have MS Outlook 2003 client outside your LAN correct. I guess..I really think it is AD some how transporting emails to each client. Although each client does have the mail server configured it so maybe it is direct sync to each client...Sorry for babbling, so you say it is called what that transport emails to the MS Outlook 2003 clients? and any port?

Thanks for helping out.Just want to know.

Thanks sprkymrk I try..

to you all

I'm quite sure no DC touches mail.

Outlook connects to a mailbox. Exchange doesn't "display" mail to Outlook. Exchange puts the messages in users mailboxes. The client connects to view it's mailbox. "Transport" is routing messages from server to server.

Something is wrong with your DCs. You shouldn't have to reboot them that often. I'd fire up perfmon or something and start gathering info on what performance metric is getting screwed (lack of CPU resources, RAM, etc.), and then start figuring out if there's a process doing it.

All mailboxes are stored in their home database. The database obviously keeps straight mail that should be able to be viewed in each mailbox.

MAPI clients tend to be internal LAN clients. Outlook Anywhere (aka RPC over HTTP) clients use full Outlook to securely access email, typically over the internet, where opening straight RPC ports to the Exchange server would be a bad idea. Regular MAPI clients use RPC to transfer mail.

Clients do NOT connect to DC's to get their mail, nor is mail sent at any time be directly handled by DC's.

itdaddy · April 2009

great thanks for explain..I guess I can do a packet sniff on my home system to see how emails get to and from exchange server...but thanks for your guys help.

Our servers go along time like 50 to 70 plus days but we like to reboot every 30 days to get them refreshed. we have never had any server issues since we implemented the server reboot in 30 days..no problems except when I let one of the servers go too long. I always think it depends on the server.so many servers are different butu if left run too long, without reboot i think weird stuff happens that is just me..

but yeah will do a packet sniff on how email is sent to my outlook 2003 clients

and let you know if it even applies or I can even see it hee hee
thank you guys for your time

itdaddy · April 2009

did a packet sniff and came up with DCE/RPC that transport the data to the client MS Outlook 2003 with TCP syn/ack inbetween..and then on server found smtp for my outbound emails..cool huh?

thanks guys

Internal Emails and External emails??

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