Email Servers





Within Internet message handling services (MHS), a message transfer agent or mail transfer agent (MTA) or mail relay is software that transfers electronic mail messages from one computer to another using a client–server application architecture. A MTA implements both the client (sending) and server (receiving) portions of the Simple Mail Transfer Protocol (SMTP). The terms mail server, mail exchanger, and MX host may also refer to a computer performing the MTA function. The Domain Name System (DNS) associates a mail server to a domain with mail exchanger (MX) resource records containing the domain name of a host providing MTA services.

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i got a customer how wants the following scenario build up in the Exchange Address Policy.
The Exchange Server is On-Premise actually.

The Example Users:

Tom Miller works since 2000 in the company

Greg Miller works since 2019 company

The actual Policy is

The Email Address for Tom Miller is
The Email Address for Greg Miller is

The Customer wants the following Email Addresses created automatically

The Email Address for Tom Miller is
The Email Address for Greg Miller is

I have at the moment no clue how to implement that.

This is very important because the customer wants to move over to office 365 in a full hybrid mode.

Thank you for some suggestions.


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Currently I have a Exchange 2007/2013 co-existence setup and i'm currently not able to login to my Exchange 2013 OWA.

When trying to access from the internal - Credentials are entered, the screen flashes and does not allow the login.

When trying to access from the outside, credentials are entered, it acts like it wants to accept them, screen flashes and does not allow the login.

As i'm getting ready to move mailboxes from 2007 to 2013 so I'm really not concerned about the redirection working from 2013 to 2007. I'm thinking this issue has something to do with how the authentication is setup on Exchange 2013. Currently is is set to "use one of more standard authentication methods" and non of the check boxes below that are selected.
I have a client with 2 exchange 2010 servers, one is very old/slow, it was operating as the primary exchange. The second exchange server is newer modern hardware with a lot of space. I have successfully migrated all mail boxes to the newer hardware exchange database. I would like to decommission the old server before it crashes and I have big problems. So what would be the process for promoting the newer exchange server and removing the old.. The public folders database is on the old server so I will need to move that as well.. Documentation for going 2010 to 2010 seems to be vague, or maybe I am not asking the right question.... Thanks in advance.

Having a somewhat surprising issue - our mail flow on our Zimbra server is down (both inbound and outbound) yet the server seems healthy and no error seems reported.

1. Server is up (8.8.10_GA_3786) on Ubuntu 16
2. Admin health status page shows every service up & running (green)
3. Webmail access is ok
4. IMAP access is ok

However, no mail is flowing in or out.

Trying to send triggers the following errors:


19:03:25 Ready to run action (retry count: 0)
19:03:25 Clearing connection to
19:03:25 Trying to connect to on port 465 (CFNetwork) with STARTTLS (required)
19:03:25 Resolved hostname (
19:03:25 Error: Connection error (Connection refused).
19:03:25 Error code: 2
19:03:25 Failed action (0). Reset observed read/write timeouts: 8/8

Open in new window

MBP13:~ alex$ telnet 25
Trying *.*.187.68...
telnet: connect to address *.*.187.68: Connection refused
telnet: Unable to connect to remote host
MBP13:~ alex$ 

Open in new window

(ie the connexion is actively refused)


method:	[unknown]
msg:	try again: Unable to connect to the MTA
code:	mail.TRY_AGAIN
detail:	soap:Receiver
trace:	qtp66233253-2518:1568314842997:7a36c58c222c3898
Body: {
  SendMsgRequest: {
    _jsns: "urn:zimbraMail",
    m: {
      e: [
        // [0]:
          a: "",
          t: "t"
        // [1]:

Open in new window

Hi Experts,

I am in an upgrade from Exchange 2010 to 2016.

I want to test the new mailflow and I like to verify the incoming and outgoing mails are just coming from the new EXCH2016 server.

Do you have some quick checks for me please ?
Hi Experts,

What's the best practice of moving an on-premises, non-mail enabled public folder contacts and calendars to O365?
This will be a hybrid migration and we'd like to decommission the PFs as a part of the project. We're aware that they'd be accessible for online users during the hybrid, but that's not an option here.

Is shared mailbox for each PF a way to go or?
What's the easiest way to migrate?

Thank you
Hi Experts,

I like to upgrade to exchange 2019 from 2016.

Is it true ?
The domain level must be on 2012R2 ?

Can you give me article from MS ?
Good Morning Experts!

We are getting ready to move our exchange 2010 to exchange 2019 (all internal-No public folders), and our office (outlook) 2010 to Outlook 2019.   (no O365)

Management wants the big jump to be all current.
After reading white papers and blogs, I’m under the impression that Exchange 2019 won’t work with Outlook 2010.

So my question is how does one migrate with the least disruption to end users?

We will be pushing out images to user PCs when we upgrade (windows 10, office 2019), on the back side "will" it go something like this…?
 - Install new 2019 Exchange server and run parallel with Exchange 2010 server, Moving the mailboxes over (2010 to 2019) as I push out the new images.

That way when user logs in to new windows 10 box, and opens outlook 2019, it will auto-discover and setup mailbox, and user is good to go??

From what I have read, I can’t install office 2019 on Windows 7 PC, and Office 2019 won’t work with Exchange 2010 (correct me if I’m wrong).

I don’t want to disrupt users that are still on Windows 7 and Office (Outlook) 2010, so I will probably push out images in groups, as not to get overwhelmed if something goes side-ways.  (as long as Exchange 2010 and 2019 play nice together)

Once all user are upgraded (Win10, Outlook 2019), I will decommission Exchange 2010 server and should be good to go on Exchange 2019 by this point.  

Does this sound like the correct procedure?
Is there a better way?

Should I wait till …
Morning All,

So, I've been tasked to create a new Mimecast policy which tags ALL external email with [EXTERNAL] and also drops something in the message body.

Now i'm trying to do this with impersonation protection and I need someone to confirm this is the right way of doing it. I don't want to use stationary to be honest.


Go to

Log in

Click administration console

Click administration at the top

Go to Gateway

Go to policies

Scroll and click "Impersonation Protection"

Click new policy: Settings bwlo

Policy Narrative  - [external] tagging


Addresses based on Both
Applies from External Addresses
Specifically Applies to all External Senders

Emails to
Applies to Individual email addresses
Specifically "My email"

Now this is where the issue is,  under options I have

So,  I go to lookup, create a new definition and I have no idea what to put in for these specific settings.


Any advice would be awesome. I only want to tag external email and I've read a number of guides but none of them specifically detail how to carry this out. I've been looking into it for a few hours now and frankly. I need some help.

Thank you all


We have emails send from Amzon server (From our domain name).

My question what is: Amazon SES Domain Verification TXT Records?

Is it an SPF record or it not the same but just another verification process?

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I need to create a Receive Connector that will act as a mail relay for an application. However this application is hosted within Akamai and can be sourced from a number of servers. I want to create a connector specifically allowing the subnets required and require the application to authenticate. The connector will have to be allowed to relay mail external to the company as well.

I just wanted to clarify what settings would need to be in place to accomplish this.

I have the following in place.

Remote Servers: only the subnets that host the application
Authentication: TLS and Externally Secured
Permissions: Exchange Servers

Would this config do the trick?

Thanks in advance.
I am understanding that a DAG is recommended but not required for an ON-prem deployment of exchange 2016. This I presume because if the 1 and only exchange server goes down no email can route.  
When a person puts in there email and password into Outlook program its supposed to automatically get the data needed to setup the email however it fails, because the exchange server has been setup incorrectly.
If we deploy a DAG will that in a step fix this issue/resolve the Auto config settings problem.

Thank you for your help in advance
We have two 2 CAS and two mailbox exchange 2013 server with no DAG.  We are facing 2 issues here.

1- Any outlook clients having mailbox on  server 1 cannot authenticate. But OWA and Active Sync is working fine.

2- Mailbox Database on Server 2 is dismounting unexpectedly. When trying to mount it throws an error message. We tried to use eseutil /mh, it shows dirty shutdown.
We tried to make software and hard repair but no luck. Created a fresh a db and but getting dismounted after some time.

Please need help and suggestions on this issue.
My "Microsoft Exchange Server Auth Certificate" is expiring in two days for Exchange 2013. I spoke with the consultant that helped me get the commercial certificate and he indicated that I shouldn't need to renew this certificate since he doesn't believe it's assigned to any services. Is there a way that I can confirm this? Am I better off renewing it anyways as a precaution?

In EAC, it does say SMTP is assigned to the Server Auth Certificate service, but it also lists SMTP for the purchased cert. as well.

Exchange 2016 Standard running as VM on Server 2019 Hyper-V --- ALL  Exchange services have stopped . This has happened 3 time over the last 4 months.
How to Justify CAL Licences ?

Hello Experts

I have a Client who acquired a Licence of Exchange . He has 4000 users at the end using the system

I explained to him that Cal are more administrative , he want me to show him in the system that the 4000 users are supported

Is there a Way to do this?

Can you see the Cal licences in the system?
I use Exchange 2010 SP3 on 2k8r2. All the incoming emails are stuck on the submission queue. Only way to release them is to restart the transport service.

I have done the following.

1. Restart the windows server.

2. recreated mail queues.

3. I use code two. To isolate the issue I disabled the code two services.

Please help me resolve this.

I have an old USA.NET email account, which I need to stop using.   I want to have emails to the USA.NET account automatically forwarded to my GMAIL account, though I don't want the senders alerted to the new address.  How can this be done?


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Hi Experts,
I am looking for a program that will keep checking at a particular folder every 20 minutes, if there were no new files created then will send an email.
This should be running all the time except for night hours (10.15 PM to 6.00 AM).
We have an Online Exchange (O365). We have multiple affected users with the same issue and is persistent across all versions of Outlook.

The users have full delegate access to a Shared Mailbox. They are able to view and access the mailbox just fine in Outlook, but the Shared Mailboxes also have In-Place Archiving enabled. These show up in the delegates users' Outlook as Online Archive - . But when attempting to access the Online Archive via Outlook, they are getting the error message:

"The set of folders cannot be opened. The file C:\Users\user\AppData\Local\Microsoft\Outlook\ - Example.ost is in use and cannot be accessed. Close any application that is using this file, and then try again. You might need to restart the computer.

We have confirmed that the users are able to connect to the Shared Mailbox via OWA and access the archives there, this issue is solely isolated to Outlook.

We have tried purging the AutoDiscover keys in the registry, creating a new email profile in Outlook, and deleting the OST files and Outlook cache to no avail.
We have an org with both 2010 and 2016 exchange all on premises.  The 2016 servers are in Europe and we originally had them using "" as UPN and primary SMTP.

The business has asked us to change everyone to a "XXX@Company.COM"  UPN and Primary SMTP.

We have users in the .eu that have been using in-place archives with no issue.  Once their UPN and Primary SMTP has changed they now cannot access the in-place archive.

They (the .eu users) are on a separate network (acquired company in process of getting onto our network) and use Outlook Anywhere.

There is a mix of Outlook Office Pro 2010 and 2016.  
We have recreated profiles and still not working,

The 2010 Outlook clients can see the archive but it says it cannot connect if clicked on.
The 2016 Outlook clients - the archive never shows up.

All of then can get to the archive via OWA with no issues, and I can add a profile from on our network with no issues and see the archive no problem.

Is this an autodiscover issue ??  What am I missing?

Thanks in advance!
I received the following error from one of our users.  We are using Office 365, but I want to confirm that this looks like another server where we are receiving the error.  This address I am assuming does not belong to office 365:

Your message wasn't delivered to anyone because it's too large. The limit is 29 MB. Your message is 43 MB.
Your message is larger than the size limit for messages. Please make it smaller and try sending it again. gave this error:
SMTPSEND.OverAdvertisedSize; message size exceeds fixed maximum size
Hello all, I have been migrating to Exchange 2016 from 2010, but most of my mailboxes are still on 2010.  I've got OWA, and ECP working well on 2016 and ready to start migrating mailboxes over the next week or so.  However, my autodiscover isn't working.

When I run the autoconfig test from my Outlook 2016, it states that Autoconfiguration was unable to determine your settings!

I've followed this guide from Adam, and as far as I can tell I've got split-DNS configured correctly, although it's murky since both servers share the same external URL's.  

Would be glad to submit configs, if someone can help me figure out where I've gone wrong.  Thanks in advance all!
AutoConfig Results
I am using Safari on a MacBook Pro.  When I check email using I get a lot of popups...particularly on the NY Times.
How do I prevent these popups from happening in the future?

Email Servers





Within Internet message handling services (MHS), a message transfer agent or mail transfer agent (MTA) or mail relay is software that transfers electronic mail messages from one computer to another using a client–server application architecture. A MTA implements both the client (sending) and server (receiving) portions of the Simple Mail Transfer Protocol (SMTP). The terms mail server, mail exchanger, and MX host may also refer to a computer performing the MTA function. The Domain Name System (DNS) associates a mail server to a domain with mail exchanger (MX) resource records containing the domain name of a host providing MTA services.