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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, on occasion we have seen malware delivered to a user’s inbox and we would like to be able to pull those messages out.

Is it possible to have a powershell command that could remove these e-mails based on items like the senders e-mail address and subject?

we have mailboxes in office 365 but we have proof point gateway through which incoming and outgoing emails go
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An important user within my organization received NDRs while replying to emails sent by someone outside of our organization.

We are using Outlook 2016 and Office 365 as our email server.

However, later on the same day, someone else within our organization was able to reply to the exact same emails and these emails reached the person outside of our organization without any problems.

Neither person sending these emails had any attachments sent as part of these email replies.

Since the person we are emailing outside of our organization is a very important person we can't send any test emails or reply to any existing emails to simply test if this issue has been resolved.

So are there any ways we can simulate sending or replying to an email to this person outside of our organization to see if the original issue with the user within my organization had with sending emails to this outside user has been fixed?
i want to set up DMARC AND DKIM,

I have proof point and mailboxes in offic e365

where do i need to set up in external DNS or any steps defined.

i believe SPF is set up in external DNS
Different employees at our company have had a problem with a large number of malicious outbound emails sent out from their company email address, causing our email service provider to shut off our service until we reset every account's password.  This has happened 5 times now.  When you look at one of the employee's Outlook programs, you don't see the malicious emails in the sent items, you only see the "bounce back" emails in the inbox, reporting that the email wasn't accepted by the recipient.  Neither McAfee nor Malwarebtyes detects malware on the employee's computer.  How can we figure out how these malicious emails are being sent out using the company's email addresses of our employees?  Could undetected malware be running on some of our computers that gives an outside person email passwords that he/she is using to send malicious emails from our accounts?  Is it more likely that our computers are sending out the malicious emails even though they aren't being logged in the sent items folders?  Could someone be intercepting our unencrypted emails and extracting the email password from them?   We have McAfee Orchestrator and a Fortigate 101E firewall appliance?  Could either of these things be used to troubleshoot the problem?
On a recently upgraded win 7 home to Win 10 home desktop PC, user uses AOL webmail.

says that from some users, when they expect an XLS or DOC /DOCX file(s), they ONLY get a file ending in WDL extension.  That's a text document that has the expected file name - kinda like a packing slip in a box.  But that's all that's attached. Not the expected file, just this packing slip text file with the WDL extension.

I told them to have the sender resend and include me.  But sender is a law firm / concerned with confidentiality (but yet, he's using an AOL address : )

So we set up a gmail account and the sender will send to both the aol and gmail accounts and we'll see if it's a sender issue.

I asked if the sender is a new employee (doesn't know how to send attachments?) - the user said no
Did the sender start using a new email system that includes a link to a secure website to get the attachment - the user said no
Are the files too large? Supposedly no.  There's a number after the file name, supposedly the file size?  in one email, it was 256.  (bytes?  KB?)

Any thoughts on why someone would get a WDL file rather than the actual file?  Yes, there's loads of ways to approach this / try troubleshooting. But getting the sender to send emails / answer questions about what they are using to send, etc. is hard.  so trying to figure things out with limited info.

googling, it doesn;'t come up with anything about attachments / emails.  WDL is some gaming file extension …
Is there a way to limit registration to certain email domains?

//email validation / only allow certain domains to register
      $allowed_domains = array("", "", "");
    $email_domain = array_pop(explode("@", $email));
   if(!in_array($email_domain, $allowed_domains)) {
    //Not an authorized email

this code isn't working, it allows all email addresses to register.

You can use IMAP or POP3 protocol to configure your Gmail account in MS Outlook. However, after using IMAP account in Outlook for some time, many users want to change their mail settings from IMAP to POP. Today we will discuss how quickly you can change your IMAP configuration to POP3.

What is IMAP?

IMAP stands for Internet Messages Access Protocol. In an IMAP configuration, the email client keeps a copy of the mailbox on the local system without deleting it from the email server. The advantage in this case is that you can access your complete mailbox data through various devices (of course with proper IMAP configuration).

Advantages of IMAP

  • Quick and easy access to emails from different geographical locations.

  • In IMAP, any items deleted from the user system is still available on the server.

What is POP3?

POP3 is an abbreviation of Post Office Protocol version 3.  When your email application is configured with POP, then all your emails are downloaded to your email application. Then emails can (and should) be permanently deleted from the mail server.

Advantages of POP3

  • Your emails are stored on your system hard drive. Each time you configure POP3 on a new device, only the additional emails will be downloaded. This saves time in configuring the email account.
  • In POP, opening and accessing attachments are quick because all the attachments are already downloaded.

Step by step procedure to convert IMAP to POP

To start this process, open MS Outlook and start the below-mentioned steps:

  1. Click on File > Info > Account Settings.

  2. Then click on New to add a new account.

  3. Select Manual set up or additional server types and then click to Next.

  4. Now select POP or IMAP and then click to Next.

  5. Enter your POP details and then click on More Settings.

  6. Then move to the Advanced tab and enter POP and SMTP port numbers and click OK.

    Note: Here, you have an option to leave copy of messages on the server for a definite period.

  7. It will take few seconds, and your POP account is successfully added to Outlook.

Steps to remove IMAP account from MS Outlook

After successfully adding your POP account, you can remove your IMAP account from Outlook.

  1. Click on File > Info > Account Settings.

  2. Then select the IMAP account and then click on Remove button, your IMAP account is successfully removed

Migrate IMAP to Cloud

Recently many users are migrating their IMAP email data to cloud emailing platforms like Office 365. This process is easy if you are using a third-party tool for migration.

Kernel for IMAP to Office 365 is a brilliantly developed and designed tool to migrate IMAP account to Office 365, hosted Exchange and on-premises Exchange. With this, you can quickly migrate those mailboxes which are configured with IMAP settings.

You can also migrate single as well as multiple mailboxes from IMAP email servers to Office 365. And this tool allows users to migrate emails to mailboxes, public folders and archive mailboxes in Office 365.

We as soon going to have to migrate off our current SBS 2008 Server. We are using the Exchange Server. The controller is concerned about the cost of moving the emails. $6 /email /month works out to $2880 per year for Office 365 email. For people who use basic email I must agree that is a lot. Are there other reliable options that don't cost as much as Office 365?
My OS is win 10 Prof 64 bit and I use office 365 and Outlook owa for my msn email account.  How do I get educated that the sender of an email is really the sender and not someone else emulating him or her.   As I get so many emails I would like to be educated on this, is there any site or video where I can discern more knowledge.  Thank u and regards.
How to restore my SENT emails in
They disappeared.  I did NOT delete them!!!!! Thousands of them.
I am using the web interface.  I have not downloaded them to my local drive.
I downloaded the email recovery add in but am NOT getting any SENT emails. Just some of my inbox.  is the link I am using even though my email address says "HOTMAIL".
I don't want to recovery any of my INBOX.  Just my sent.  I have thousands  of SENT messages that I need to recover.
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What is the correct process to use to set up an Outlook 2016 Gmail account to save emails to a PST file instead of an OST file?
We have a single user who is unable to send email outside of our organization due to multiple kickbacks with following NDR
Remote Server returned '550 5.7.501 Service unavailable. Banned Sender
I have verified by searching the various online spam lists ( spamhaus, etc) that our domain is not on any list and the issue does not seem to be effecting any of our other users. This user had his account hacked last week and we discovered it was used to send a large amount of spam before we reset his account.
I am unable to find a solution to resolve kickbacks for a single email address.
There's an external application server (IP a.b.c.d)  that send email blasts to a
team/dept in our organization but we block this IP in our exchange/domain
because it is sending with the sender in the email header as

What are the risks & mitigations we can put in place if we were to permit a.b.c.d
to bypass from Norelay (sender and recipient email address from same domain)
I want to clarify my underderstanding of the Email process to multile recipients as seen using MS Exchange versions.

I am wokring thru a problem for a client.  My understdning is that when a users send an email to multiple external recipients in the following context:

The sending server :
  • Sends each email recipient a separate copy of the email
  • does not group emails of the same domain (e.g. as one email for the receiving server to "distribute" in its own processing
We use exchange pop3 software to download emails from externally hosted email server and to forward exchange 2007 server.

We stopped this software and we are migrating our exchange server from 2007 to 2013.

We moved all users from exchange 2007 to 2013.

But when we restart the 2007 server, by mistake exchange pop3 server started automatically to download emails and forwarded them to the exchange 2007 server. And those email are not reached to 2013 server and get stuck in the queue of 2007.

How can we release them to the users.
What are the steps to create an SMTP relay account within Office365?
I'm trying to understand how to track messages around Exchange to thwart phishing attempts quickly.

Is there a way to see if a message was opened?

Is there a way to see if an attachment was opened?

Is there a way to see if a user forwarded a message?

Thank you,
We have been struggling with setting up our website on a GoDaddy Virtual Private Server. Please Help!

We have a .net program that connects to First Data to process credit cards. It running on a Windows 2012R2 + Plesk Virtual Private Server hosted at GoDaddy.We need to send confirmation emails from the server after a transaction is processed. I am attempting to send an SMTP email on a GoDaddy Plesk VPS and am having difficulty with the syntax.  Here are examples of what has been tried with the corresponding error messages.

What are the correct APC Office 365 SMTP email server settings for sending e-mail notifications using an Office 365 account?

According to the website port 587 with TLS security is used but I don't see any place to enter the port number and encryption method within the APC SMTP server settings (see the screenshot).

So how can I correctly configure the SMTP email server settings to send email using an Office 365 email account?

APC email server settings
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I'm having an issue getting SMTP (outgoing) communication to work for a program on an application server.

I need help from an expert to identify what SMTP settings i would need to apply for my situation. I currently have it set as SMTP port 25 no TLS, no authentication required. Ive tried many combinations of those settings as well. All have failed.

I can access any of the servers we need to piece this together and also have access to Exchange in all regards.

The program in question is Manage Engine Service Desk and we have an on-premise Exchange 2013 CU 19 environment. The server the program resides on is Windows Server 2012 R2.

I'm curious about powershell commands that reveal the current SMTP settings and can maybe test connectivity from the application server to exchange itself, things like that. Im really stumped on why this doesn't work. I think it should be easy. Than again when we say Exchange i envision a large mountain. :)

Thank you for any help on this
IMAP vs. POP vs Exchange (are there others than these?)

I think I know the basics -
exchange deals with contacts and calendar also (POP and IMAP don't).
POP takes emails off the server (OK, it could leave it on the server too) & sent messages stay only on the device
IMAP - is it wrong to call it the poor man's exchange?  

More of a real life situation - usually small businesses have shared hosting for their domain.  And limited space for storage as part of the shared hosting...

So while IMAP is 'better' than POP (since all the sent / received mail is in 1 place - on the server, regardless of the number of devices you use to check mail, keeping all your mail on a shared hosting plan for a bunch of employees can fill up your storage allotment?  Right?

JUst like to hear experts thoughts on why you like 1 over another (but don't think I need a lesson on the differences) / does 1 method not work realistically?

Does imap on a cell phone with lots of past emails / folders and keeping all that in sync burn up lots of data?
I know getting a new phone and getting sent items from a pop account is a pain.

Seems exchange is the 'optimal'? Is that safe to say?  you get big mailboxes (I am thinking office 365), contacts, calendar in sync across devices and between employees if you want.

But the cheapest way to get exchange?  $4 / month?  I heard is now using exchange? That's free and you get calendar and contacts? But yeah, an address.  Or …
Helping my brothers who are very low tech.  

They have their own domain. Hosted at a shared hosting company. They check / send their mail ONLY from the webmail of the hosting company.

They are moving the website to another shared hosting company (and setting up email at that new company also I would think).  They are asking me about getting / saving all the the old emails on the first hosting company.

I know I could use my outlook, set up a POP account and download the inbox for each account.  But other folders?  Sent?  

Maybe I'm not much more techy than them - should I really set up outlook for IMAP?  then I can export ALL the folders into a PST?

Next issue - they don't use / have  outlook. Can that PST of inbox / sent / etc be pushed up to the new server? (set up imap to the new server, and drag /drop emails from the PST into the IMAP appropriate folders?

If that won't work, then what would you recommend for someone that is using just the webmail of the hosting company but want to see the old emails once in a while?  Thunderbird for the old emails?

I have a situation where a supervisor needs to monitor a subordinate's email. The problem is that the supervisor needs to be able to check the messages from an iPhone, and we are trying not to have read receipts go back to the emails of people that send to the subordinate. I have been testing on an unrelated device with an unrelated account, and have gone as far as completely turning off read receipts for the Exchange account in my OWA settings- still returning read receipts, even after 72+ hours of being turned off. I'm not scared of changing Exchange settings, and I'm not scared of powershell. Is there a way to fix this without upgrading Exchange from 2013 to 2016? I know 2016 supports doing this... If there isn't a settings way to change it, can you recommend a transport rule that will accomplish this? I have full control of my Exchange environment. This is working properly on an android, so I think it has to be solved differently for the iPhone. I need the iPhone way to work.
I have a user that wants to be in 2 dynamic distro list. Distro list A looks at OU A and distro list B looks at OU B. THe user is in OUT B/Distro B, but he wants to be added to OU A/Distro A and get emails from both. I don't think you can do that, can you? If so, how can i do that without moving the users out of there OU.
I am having a customer that is attempting to email us and is getting an error on their email servers.

Connection for delivery was deferred by "my.mail.server"
 and they are getting a 4.4.2 error that is coming from my mail server

Mail server is running postfix, but I do not see this particular email address in the logs. I see other email addresses from the same company successfully show up in the logs, but not this particular one.  Client is putting additional pressure to figure out root cause.

Any thoughts?


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.