Email Protocols





Interactions between email servers and clients are governed by email protocols. The three most common email protocols are POP, IMAP and MAPI. Most email software operates under one of these (and many products support more than one).  The correct protocol must be selected, and correctly configured, if you want your email account to work.

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Dear Team, we are suffering the slow problem of Email Exchange 2016: Send from Exchange server is OK, but receive is slow; which ever have or does not have attachments.

We have Avast installed in Exchange server, everything in default mode, not sure which Exchange part should be added to AV's exclusion.

Is there any other way for tuning or increasing the speed (except increase the bandwitdth, we are in Leased line link: 30 Mb/s International + 50 Mb/s Domestic)?

Many thanks as always!
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I have an enormous problem about my disk quota .
Everyday tons of emails enter my mailboxes
I have a plan to pull all my email to sync in local folder. So my i can freed my corporate email
Are there any tutorial to pull all of my corporate email via Thunderbird ?
POP3 or IMAP kindly accepted


Romi Nur

We have a client who has just had a DKIM domainkey setup for them. Unfortunately some emails are not getting through to the end users (especially if using Mimecast mail servers).

We have been doing some testing and have found that:
Emails that do not have an attached file - it pass the DKIM checks.
If emails have attached documents, they seem to pass OK as well.
If emails have got an attached email that was originally from the sender, it passes OK
If an email has an attached email from a third party (that has originally been changed with DKIM) it fails the DKIM test on our/the recipients servers. This has happened to us and we use exchange online servers.

When it fails it says dkim=fail (body hash did not verify)

They have a valid SPF record also setup and every email through the testing procedure seems to pass on the SPF checks without any failures.

There is no DMARC record setup yet, but as far as I can see this is the next step after we have got DKIM working correctly.

Unfortunately our client who is having this problem quite often forward a lot of emails during their working day so need this resolving.

Any help would be appreciated.

outlook email alerts not coming. How keep alerts so that when email comes popup comes and also preferably some sound comes?
please advise
Dear, I tried but could not start this service. Does anyone get this error before? Can you please help?
Many thanks in advance,
"The Name on the security certificate is invalid or does not match the name of the site"

We have a user who is experiencing this error when traveling . Problem only occurs when connecting to MS Outlook via a hotel or public wifi, but not all of the time.

Similar issue occurred two weeks ago on the same user's cellular phone (as well as a coworker he was traveling with). Both employees were out of state when this happened

  • We have other employees who travel out of state who have reporting nothing
  • We are on Exchange 2010
  • User is on Outlook 2010 client
  • Validated with Godaddy, our certificate issuer that the certificate is perfectly fine
  • Validated with MXToolbox that mail autodiscover resolves fine
  • User connects perfectly fine from home, which is also out of state (remote worker)
  • Issue began two weeks ago, making this problem seem like more than a coincidence

If there's anything else I should be looking at, I'd love to know! TY -Dave
When I email users from one particular company domain (and only that domain) they get my email from my company domain email, but when they reply (and also if they just directly write to me)  it doesn't come to my company email, even though on their outbound email that is what shows as the 'to', instead it arrives in my personal yahoo email, even though the sender couldn't even possibly know what my personal yahoo email is.

This happens for any sender from this particular company to me, but the same doesn't happen when that company sends emails to anyone else in my company, they work fine. They also say they never had this problem with anyone else. I do not have any forwarding of any kind of redirect set up in my email system. None of my other colleagues have any issues receiving emails from this company.

Looking at the header of the message I receive it shows

X-Apparently-To:; Thu, 27 Jul 2017 07:39:28 +0000
Return-Path: <>
Received-SPF: pass (domain of designates 104.4xxxx as permitted sender)

Authentication-Results:; domainkeys=neutral (no sig);; dkim=pass (ok)
Received: from  (EHLO (xxxx)
 by with SMTPS; Thu, 27 Jul 2017 07:39:27 +0000
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=selector1-sender-com;

From: Asxxxxx…
Hi All,

When I enabled / redirect the Postmaster email from my Anti Spam appliance, I got to see the below emails coming in hundreds of them daily to my mailbox with the below error:

550 5.7.1 Bounce attack signature verification failed. (in reply to RCPT TO command)
550 Administrative prohibition - envelope blocked - (in reply to RCPT TO command)
550 #5.1.0 Rejected by bounce verification. (in reply to RCPT TO command)

How to resolve the problem above ?
Help! I spent a few hours drafting a long heartfelt email to my children and when I hit save it save draft. Now I have gone to my saved draft folder and it is not there. Is there anyway to still retrieve it or am I sunk?
Dear Team, does anyone know how to configure 2 steps authentication in Exchange mail server? Is it possible? many thanks in advance.
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I would like to make a parse of postfix mail log in an HTML/PHP page with a search bar and then creating a dynamic table with all these tags. when the table is done I should be able to click on the "Date" and another page should open with others info about that log *(2)

I will copy an example of a log

search: from: ...... to: ...... date: from: .... to: ....

Eg Table example: Date | time | from: Jack | to: John | status:


status detail

809318:Jul 11 14:13:50 amail-2014 postfix/smtpd[17127]: 78F5E83F28:[]
809320:Jul 11 14:13:50 amail-2014 postfix/cleanup[18135]: 78F5E83F28: message-id=<>
809324:Jul 11 14:13:50 amail-2014 postfix/qmgr[27711]: 78F5E83F28: from=<NO-REPLY@MOLEX.COM>, size=30390, nrcpt=1 (queue active)
809325:Jul 11 14:13:50 amail-2014 postfix/smtp[11782]: 78F5E83F28: to=<*****@SYLEX.SK>,[]:25, delay=0.73, delays=0.59/0/0.01/0.13, dsn=2.6.0, status=sent (250 2.6.0 <> [InternalId=50607599648815,] Queued mail for delivery)
809326:Jul 11 14:13:50 amail-2014 postfix/qmgr[27711]: 78F5E83F28: removed
809323:Jul 11 14:13:50 amail-2014 KLMS: not processed: …
I got a mail from was it real or not please tell me
I have one client that cannot email me.. They receive a bounced back message saying;

550 Verification Failed
No such user here
Sender verification failed

I can however email them. But they cannot reply.

None of their emails from their domain will come through, however I have been guaranteed from my ISP (crazy domains) that there are no blocks on my end. However i do know of another company who are with crazy domains are experiencing the same problem with the server  

As I run my ow  business, my only option is to change hosting companies in the hope that works.

Would love an easier fix
Hi All,

May I know where shall I manually add the below entry if I handle the Public DNS using Windows Server box in my DMZ ?

DKIM: Create a CNAME record for with this value:

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SPF: Create a TXT record for with:
v=spf1 ?all

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What is the risk or issue when implementing it during the business hours ?
I am trying to setup subscriptions through our reports server generate reports and have them automatically emailed to external addresses.
I am using SQL Server 2012
Reporting Services Configuration Manager
Email settings:
Sender address:
current smtp delivery method: use smtp server
smtp server:

WE do not have a local smtp server setup so if I can use google smtp or some other method to send mails from the reports server that would be great.

Thanks for your assistance:


Facing an issue with one company, that I can't receive email from them !!
Wwe have our own mail server as they do , they have Exchange Server as they mentioned,and we have SPAM Filter Appliance but the email never reaches SPAM Filter in order to be checked and sent to Our Mail Server.
Our Domain is hosted  with hosting company and they are pointing MX Record to our public IPs .

What are the steps to troubleshoot the issue ?

Thank You
Dear All,

I have a question. When my clients send their transactional emails using my provided SMTPS, I process the MTA logs to generate bounces and track emails. I need some guidance here, how would I put my web application in the middle of MTA and the client so if any client sends any transactional email using the provided smtp, it pushes the email to my application first and then my application pushes it to the mta after filtering it.

Thank You
Like the title says, we are missing Outlook 2013 calendar entries and contacts.

We are not using Exchange, but we are using an ost file. I did an Outlook scanpst, and Outlook repair. Some of the messages were gone, so I deleted the .ost file to allow it to rebuild. Although all the email messages have returned, the Outlook Calendar entries and contacts are gone. How do we get those back? This is just one PC that is affected. Thanks.
I am receiving the following error when truing to setup Microsoft Exchange 2013 on a new server. I have followed all of the instructions noted in Microsoft's guide:
However when I run the installer it throws this error when setting up the "Mailbox role: Transport service."

The following error was generated when "$error.Clear(); 
            if ($RoleProductPlatform -eq "amd64")
                $useAttachMode = $false;
                $fastInstallConfigPath = Join-Path -Path $RoleBinPath -ChildPath "Search\Ceres\Installer";
                $command = Join-Path -Path $fastInstallConfigPath -ChildPath "InstallConfig.ps1";
                $fastDefaultDataFolderPath = Join-Path -Path $RoleBinPath -ChildPath "Search\Ceres\HostController\Data";
                $dataFolderPath = $fastDefaultDataFolderPath;
                if ([System.IO.Directory]::Exists($fastDefaultDataFolderPath))
                    $useAttachMode = $true;
                    if ($RoleIsDatacenter -eq $true)
                        $preferredDataFolderPathRoot = "D:\";
                        if ([System.IO.Directory]::Exists($preferredDataFolderPathRoot))
                            $dataFolderPath = Join-Path -Path 

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Hi All,

Our environment runs exchange 2010. Recently we have found that we are unable to set up SMTP on devices (scan to email on copiers, email notifications on various things). Details are entered in correctly at the device but the test always fails with a generic error (unable to send email) etc.

Some other devices on the same network seem to be able to send SMTP notifications without issue (e.g. our UPS). If I copy the exact SMTP details in a device that isn't working, to one that is. The email sends, indicating to me that the actual settings are ok?

The only reason I can think of to cause this would be that some devices require something additional that our Exchange Server doesn't have configured?

We have no known issues with our Exchange server. I've had a look at "Receive Connectors" in Exchange, and tried adding in a new receive connector for the IP address of a device that isn't working, but it doesn't seem to solve the issue.

What should I be looking at to ensure that all devices within our network can communicate via SMTP?

I have tried testing SMTP using a few tools, using "bmail" from here:

I can successfully send an email from any made up address to a valid address in our organisation using the below example command:

C:\> bmail -s MyServer -t -f -b "This is a test" -h -a "This is the subject"

That works.

Using TELNET and …
I changed the password on a account and now it is failing.  It keeps asking me to put in the log in and password and when it tests an email, it fails to connect to server.  I have tried deleting the email and reinstalling it.  It won't reinstall it.  I have tried using the old password.  Nothing is working.
I am setting up an email account on Outlook 2016 with IMAP server settings.  When I delete a message I want it to go to the delete or trash folder but remain available for future reference.  Is there a difference between trash & deleted folders?  I have UNchecked both boxes in the "deleted items" for internet email settings".  Thanks in advance for your thoughts!
I have a Server 2012 R2 with Intel Active System Console running.
I want to receive emails on Critical Events.
I need to configure Mail Server Address, User ID, Password and Recipient Email ID.
I use my ISP's SMTP server address for the Mail Server Address.
It doesn't require authentication but I am forced to put in a User ID and Password.
There are no options for configuring ports or encryption.

What User ID and Password do I use? The one I use to log into Intel Active System Console or one for the email server?

How do I test this is working?
I have Dropcam (now Nest) forward mail to three different email addresses.  Often, one relay entity is very slow (just now, 111 minutes).  This is usually ""  Why and what should I do about it?
I want my mail address back

Email Protocols





Interactions between email servers and clients are governed by email protocols. The three most common email protocols are POP, IMAP and MAPI. Most email software operates under one of these (and many products support more than one).  The correct protocol must be selected, and correctly configured, if you want your email account to work.