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 am trying to send email through an application on the server.

From: ABC
Reply to:
Domain: internal

user: db.admin
password: password for this ad account

I get following error on test email:

javax.mail.AuthenticationFailedException: 535 5.7.3 Authentication unsuccessful

It looks like I am not able to authenticate using this account db.admin ? or is it something else ?
I am running exchange 2010.

Could it be the possibiltiy that this account is not authorized to use SMTP relay ?  If yes, where in exchange 2010 exactly I can go and see all the accounts those are authorized ?

Thank you!
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problem started 2 days ago, we are currently using mapilab to redirect our incomming emails from external smtp to our exchange server.. emails are not being sent to users, instead its going to C:\MAPILAB IN\Bad folder .. to fix this temporarily, all i have to do is to restart the Microsoft edge transport services and that would solve the issue. Later on, it became worst, i had to restart the server to fix the issue. Checked the mapilab logs, im getting the insufficient resources error.. checked drive capacity, still have 59gb free.. i also checked online for some solution and that is by editing the edge transport config thru note pad and adding the required line so it wont check resources, that didnt work.. also tried to see if i can just manually move the incomming mails to the default pickup folder C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\Pickup and that didnt work as well.. so I am running out of options now, i just need a temporary fix then later on during weekend, i will move the entire database to a higher capacity drive..
I have an older exchange server which is working without a problem on my current ISP.  I had to switch ISP's recently and my old ISP will be disconnected shortly.

Unfortunately, even though I WAS told my new ISP can provide rDNS for my on-premises email server, I am now being told they cannot.

I have a "persistent-IP" which is ALMOST a static public IP, but it must be from a block of public IP's they have in which I am probably being natted.

So, is there a way to setup a third-party rDNS so my emails from my on-premises server do not end up in spam or bounce?

Dear Wizards, we have an Exchange 2016 server, domain:, after times, Boss wanted to change email domain to, then we configure the Accepted domain in Exchange server to; but the AD server 2012R2 still is

Now, we would like to change the AD to as well, but still keep the Exchange server working.

Is it possible? if so, can you suggest please? Many thanks!
I've selected details like
but I encounter issue below. Why?
Hi Guys,

We are in the process of setting up Exchange DAG.

Whilst the DAG is still in the planning phase, can a live copy of the Exchange mailbox database be created on the same server in the meantime?

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.


Hi Expert

I tried a lot of time to migrate public folders from exchange 2010 sp3 to exchange 2016 and I am still getting the same error

(( Error: Property expression "Library for Organizational Forms" is invalid. Valid values: Strings formed with characters from A to Z (uppercase or lowercase), digits from 0 to 9,!, #, $,%, &, ', *, +, -, /, =,?, ^, _ , `, {, |,} or ~. One or more periods may be embedded in an alias, but each period should be preceded and followed by at least one of the other characters. Unicode characters from U + 00A1 to U + 00FF are also valid in an alias, but they will be mapped to a best-fit US-ASCII string in the e-mail address, ))

I search online and I found this article I did what this article said but no result

I saw many articles online but none of them helped me

So now I am thinking about to export the whole public folder to PST file

Then destroy the old public folder DB on exchange 2010  then create a new one on exchange 2016 then create the public folders manually then import the PST

But the big disadvantage of this approach as I know the whole ACL will go away and I have to rebuild them again right?

This command will backup the ACLs for …

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.
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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 ?
Configuring Exchange Web Services

Following this article:

I would like to know if the configuration of the mentioned web services is done on the CAS server or can be done on any Exchange Server role ?
on the similar context, the author wrote an article here:

but it did not explain what is the difference between Default Website and Exchange Back End in IIS Manager.

Any Help will be very much appreciated.

Thank you
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?

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.
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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?

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.