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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we have a mail server protected with a well reputed firewall, and published in internet
we have lots of traffic with external users who never complained about sending mails to our domain users,
lately, there is a provider who has four different mail domains which are hosted in different corners in the world, but cannot send mails to our organization...
we checked everything a out our domain:
* mx records
* DNS publishing
* internal mail servers
but nothing seems to be incorrect or blocking sender domains, but the user is always receiving this message error:

host lookup did not complete

which is generated from a CPannel webapp,
i add, that both of us (our organization and external provider) are able to send/receive emails to other domains without a problem

I don't know what I should exactly check or what I can do to resolve that issue?

thank you
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I am using hotmail, if I ever marked any email as Junk or Phishing or clicked Block, will hotmail automatically inform the sender’s server about I marked their emails as spam? I recently noted that a genuine sender said I marked their emails as spam previously (which I did not recall I did), and they stop delivering any emails to me now until they reverse this situation from their servers.
We have two Exchange 2016 servers in a DAG that we recently removed and deleted the DAG from our environment.  I was going to give it a day before decommissioning the two Exchange servers; however, I did notice when looking in the transport logs under "message tracking" that I am seeing errors like No suitable shadow servers,,SMTP,HAREDIRECTFAIL, & ExplicitlyDiscarded.  I have not seen before and no email should be hitting these servers.  Is there something I am missing after I removed the servers from the decommissioned DAG? We are in a hybrid configuration but we have two other DAGs in play.  

Also, can someone provide me with the procedures to decomissioning a Exchange 2016 server?  Just curious how everyone goes about their routine.
Dear Experts

I am hoping someone can assist me with the following issue. I have SPF and DKIM configured on my domain, which appear to be setup correctly but when I examine the message header of an email I sent I see the following entry "None ( does not designate permitted sender hosts)"

Just to add I am using Exclaimer for signature management.

Please can someone examine the header below and advised if I configured something incorrectly.

Received: by 2002:a4f:c15:0:0:0:0:0 with SMTP id 21csp930979ivm;
        Wed, 21 Aug 2019 06:30:56 -0700 (PDT)
X-Google-Smtp-Source: APXvYqyk6Zvuz4Zzp1WUwoJQlz3EsF/mENO5B7uNOXkWXKiQUJ9CmIl25//eS3gDvDa/NqaFIZJg
X-Received: by 2002:a17:906:158c:: with SMTP id k12mr31626198ejd.83.1566394255976;
        Wed, 21 Aug 2019 06:30:55 -0700 (PDT)
ARC-Seal: i=2; a=rsa-sha256; t=1566394255; cv=pass;; s=arc-20160816;
ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed;; s=arc-20160816;
I have an Exchange 2016 DAG setup with 2 servers having the "Content index state" failed and suspended.
Actually on server1 it is failed, and on server2 it is suspended.
Using Exchange powershell commands to catalog the DB did not work most likely because no valid index is available.

What should I do to fix this?
Let say i have an exist email address A that send alert to few administrator about server/system health status.

Do i need to create mailbox for this email address? or just the mailbox contact + mailflow rules would be sufficient enough?

Please advise.

resource user email account want access to send email to groups email account so that each members in the group recieve mail from resource  user email account.

Please let me know how to make policy or rules


A = group user email id (x,y,and z are members of A group)
B= resource user email id

B wants to send email to A group .. so that all users in the group A will get emails from B
Exchange 2013 delete deleted items , permanently. via power shell
My office has been using Exchange to run our email system but a month ago we switched to our own domain and moved our email system to that domain.

We're using Outlook as a client.

Meanwhile I had not cancelled the Exchange subscription and now we're getting 2 separate and unique sets of emails to the same single email address.

It seems that anyone who replies to the "mail on the old server" will have their messages routed to the "old mail server" inbox. And anyone who replies to the "mail on the new server" will go to the "new mail server" inbox.

1. If I cancel the (old) Exchange subscription, will "all NEW replies to the mail on the old server" be automatically routed to the "new mail server"?

2. What is the most efficient method to combine the two sets of mail? Is there a software or specific way to bring the "original server mail" to combine with the "new server".  I don't want to risk deleting or overwriting a bunch of old mail.

Thanks in advance for any advice!
Our organization is using Exchange Server 2013 and each user requests delivery and read receipts. We've had weeks/months where it worked flawlessly (at least they didn't tell me it wasn't working). Then a month where they get the read receipts, but not the delivery receipts. Then the same thing only sporadic over the course of a week.

We had a ticket open with Microsoft last year about it and they remotely connected in to our server and confirmed the settings were correct to allow the receipts on our end, but they also noted the tracking receipts for users are unreliable as well as dependent on the recipients server.

That being said we've got read and delivery receipts from the same external users, then not received them. In that example the external users are a local company across the street from us so we confirmed with their IT that they allow delivery/read receipts.

I am officially stuck at this point and the big guys are getting upset now. I've been trying to talk them into a third party solution, but penny pinches are pinching. Is there anything I can do to on my end to dig further into this?
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We’ve posted a new Expert Spotlight!  Joe Anderson (DatabaseMX) has been on Experts Exchange since 2006. Learn more about this database architect, guitar aficionado, and Microsoft MVP.

2 - SMTP servers in the same domain, Exchange 2010 and Domino App's Server. The Domino server runs several custom programs and use "mail-in" Databases. Essentially the database has an Email address and that is how data is sent to the server. The domino server sends email out the Exchange addresses and needs to receive email from an account on the exchange server that needs to forward it to the domino server.

My first though was, I think Exchange can use a send connector to forward any email addressed to a certain mail address to another SMTP server (ie the domino server) but I can't find a document that explains that. The other option I thought of was to use the Global Domain Document to create another alternate SMTP Domain on the Domino server. IE incoming mail to XXX.XYZCompany.Com that hits the exchange server, would have a rule that forwarded mail to which is a subset DOMINO.XYZCompany.Com ... I am looking for input how to handle this.
Hi Experts,

I have two servers running Exchange 2016  and Exchange2019.
All mailboxes and public folder on the EX2019.

Question: Is Impersonation working with EX2019 ?
Because on my end not or I have something forgotten within the upgrade.
Any Ideas ?

When I test with EWS-Editor, IMPERSONATION is working to the EX2016 but not to the EX2019.
I would like to know if it is possible to find an open smtp relay in internet that i can use with telnet to test if there are any issues with our antispam hardware.
thank you in advance
Dear Experts,

We are using Wordpress on Bluehost for our website, and using WP Mail SMTP plug-in to send out acknowledgement emails after we receive a request.  We are having issues because our client, who is receiving this request mails use Mimecast, and they see this as spoofing, because All email for Bluehost's shared hosting customers is routed through a pool of proxy email servers.  We cannot white list a range of IPs because they seem to change all the time.
We tried other plug-ins, but the issue always remains the same.  
Please advise.
I have a problem with sending email to live, hotmail and outlook , really i don't know where is the problem.

i send an email to gmail account, icloud account  & outlook account.

1) gmail accept the mail and received on inbox
2) icloud  accept the mail and received on inbox
3) outlook received on spam

the following link is for my mail test  :

Received: by 2002:a17:90a:8805:0:0:0:0 with SMTP id s5csp1386721pjn;
        Thu, 19 Sep 2019 13:06:28 -0700 (PDT)
X-Google-Smtp-Source: APXvYqxVrVbbWbFogAm2aVdUExtQ6b0N55qSu7fXvBPqoaWxMj9NghrKlEHB2rYmNyeXadlr1u8a
X-Received: by 2002:a05:600c:22d9:: with SMTP id 25mr4001240wmg.133.1568923588209;
        Thu, 19 Sep 2019 13:06:28 -0700 (PDT)
ARC-Seal: i=1; a=rsa-sha256; t=1568923588; cv=none;; s=arc-20160816;
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed;; s=arc-20160816;

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Dear Experts
We have to deploy mail server on-premise for which we have thinking to go for microsoft exchange server.
my network consists
•      server virtualization -vmware infrastructure.
•      two ISP’s for high availability and windows AD for user management.  
•      CISCO ASA with FMC  
The user base we are looking for email server is too small that is 25 users. please suggest the email security solution that we should be considering  please recommend few best products for the email security. thanks in advance.

i don't know why my mail server is marked as spam , i create a dmarc record , spf record and DKIM record

when i try to send to outlook it's going to spam
this is the original message.

Received: from
(2603:10a6:209:14::19) by with HTTPS
via AM6PR0102CA0006.EURPRD01.PROD.EXCHANGELABS.COM; Mon, 16 Sep 2019 18:03:53
Received: from
( by
( with Microsoft SMTP Server (version=TLS1_2,
cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.20.2263.14; Mon, 16 Sep
2019 18:03:53 +0000
Authentication-Results: spf=pass (sender IP is;; dkim=pass (signature was verified);; dmarc=pass action=none;
Received-SPF: Pass ( domain of designates as permitted sender);
Received: from ( by ( with Microsoft SMTP
Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id
15.20.2263.14 via Frontend Transport; Mon, 16 Sep 2019 18:03:53 +0000

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On vtiger 7 (hosted on debian server), the workflows are not sending emails.

The email settings are correct because i can send emails manually.

Any suggestions on what I can look at and change?
Exchange 2010 server trying to complete a mail Multi-Mailbox search, we have done this using the discovery search tool as well as in powershell in the past but recently this has stopped working.  If we start a search it will never progress beyond 0%.  

So I did a discovery/estimate step without moving the mail to a discovery search mailbox and it worked, found the 9 items I expected searching my mailbox, tried a bigger search across the multi-mailbox and it came up with 300+ hits.    

On my small discovery/estimate search I changed it to moving the mail items to the discovery search mailbox and it still stuck at 0%.   I created a new discovery search mailbox in case there was a problem with the first and I get the same results, stuck at 0%.
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We had Exchange 2007 server and to migrate the mailboxes to 0365 , our onsite engineer told that we need to install  exchange 2013 for hybrid environment.

Exchange 2013 was installed  and after migrating the mailboxes from Exchange 2007 server and to 0365, i demoted Exchange 2007.

Now only Exchange 2013 is on the network.

Firstly , do i need to have the Exchange 2013 server still on our network?

Secondly , where do i find the settings if the Exchange 2013  server configured for Hybrid

Any help much appreciated.
I am trying to send email using email relay server which I have setup on postfix.

[root@email postfix]# mailq
-Queue ID- --Size-- ----Arrival Time---- -Sender/Recipient-------
C7792185E7F1      451 Sun Sep  8 15:27:48
(SASL authentication failed; cannot authenticate to server[x.x.x.x]: no mechanism available)

60870185E7F2      451 Sun Sep  8 16:52:57
(host[x.x.x.x] said: 454 4.7.1 <>: Relay access denied (in reply to RCPT TO command))
This is a huge issue in the company and we're trying to find a solution. We want the contacts in the GAL to be able to sync with the users smart phone. It seems like this wouldn't be rocket science, but can't seem to get it to work. I have ActiveSync on the phone and it authenticates to my account because when using Outlook app, the contacts appear there. Listed in my contacts app is the Activesync account, however NO contacts show up under it as if it's empty. I've checked to ensure that Contacts is checked as far as syncing goes. but can't seem to get it to work. Any help would be greatly appreciated. Thanks!
Can a forward be placed on a Gmail account which has been moved the the Vault? (Leaver)

We have many cases raised for a shared mailbox type setup for a leaver's mailbox so that historical email and forwarding can be put in place for another staff member.
We are finding that certain users are unable to login to the Mimecast portal.  It is always a user where their username changed due to getting married or something similiar.  We are on Office 365.

So , for example, Mary Smith ( got married and became Mary Jones (   Typically we just create an alias email for the new name without changing the Office365 username and everything works great.  However, these users cannot authenticate and login to the Mimecast portal either with EITHER email address.

Not sure if anyone has run into this and if it is just a quick fix setting change somewhere.  Mimecast not too helpful on this so far saying it is an office 365 issue.
Started yesterday, can't connect to exchange- Outlook, owa, activesync or ecp.  Got a new cert last Monday.

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.