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54 votes

Good idea? Refuse incoming emails with our own domain ending? (because they must be fake)

Yes, if you know that email for your domain should only be coming from your own server, then you should block any email for that domain originating from a different server. Even if the sender's email ...
DKing's user avatar
  • 826
32 votes

Good idea? Refuse incoming emails with our own domain ending? (because they must be fake)

There is a standard for doing this already. It's called DMARC. You implement it with DKIM signing (which is a good idea to implement anyway). The high level overview is you sign every single email ...
Mark Henderson's user avatar
11 votes

Good idea? Refuse incoming emails with our own domain ending? (because they must be fake)

Such a block is likely to reduce spam and possiblly make social engineering harder but it may also block legitimate mail. Examples include mail forwarding services, mailing lists, users with ...
Peter Green's user avatar
  • 4,316
10 votes
Accepted

How to determine if remote wipe succeeded?

As written in the MS documentation here: The remote device wipe feature also includes a confirmation function that writes a time stamp in the sync state data of the user's mailbox. This time ...
BastianW's user avatar
  • 2,888
6 votes
Accepted

Where is the global address list stored in AD?

In ADSIEDIT: Configuration [.contoso.com] ◦CN=Configuration,DC=contoso,DC=com ◦CN=Services ◦CN=Microsoft Exchange ◦CN=OrganizationName ◦CN=Address Lists Container ◦CN=All Global Address Lists ...
yagmoth555's user avatar
  • 17.2k
6 votes
Accepted

Outlook Web Access, Exchange 2013, Malware

No, opening the message through OWA wouldn't have any impact on your Exchange database. Are you using any sort of spam filtering solution in your environment? If not, you should be... Basically, you ...
ewwhite's user avatar
  • 198k
6 votes
Accepted

Will a mailbox user know their mailbox has litigation hold?

Litigation hold and In-place hold are transparent to the user, so they will not know they are on hold. https://technet.microsoft.com/en-us/library/ff637980(v=exchg.160).aspx
Michael Brown's user avatar
5 votes
Accepted

how to backup/export office 365 email to pst in exchange hybrid environment?

You can't export Exchange Online mailbox directly to PST via PowerShell with built-in tools. Required New-MailboxExportRequest doesn't exist Online (or is not exposed to us mortals). You can: ...
Don Zoomik's user avatar
  • 1,543
5 votes
Accepted

Reserve Email Addresses for old users within Exchange organization

Delete the mailbox and user account. Create a Distribution Group and name it using a name that describes it's purpose (like Placeholder or something to that effect), then hide it from the Address ...
joeqwerty's user avatar
  • 111k
4 votes
Accepted

Exchange 2013 DAG Cluster Unable to add second sever

Mixed OS version clusters are not supported. Get all of your servers on the same version. See: Planning for high availability and site resilience (Microsoft Technet) Each member of a DAG must be ...
longneck's user avatar
  • 23.2k
4 votes

How to delete mailbox from database and release the storage?

Deleting the mailboxes isn't going to reduce the size of the mailbox database file. You need to perform an offline defrag of the mailbox database to shrink the file. You might be better off moving all ...
joeqwerty's user avatar
  • 111k
4 votes

Slow SMTP responses with Exchange 2013 (Not network infra related)

The behavior you are witnessing might be a security feature called SMTP Tarpit. It slows SMTP responses on purpose to mitigate some attack types, like directory harvest attacks. The setting is ...
J-M's user avatar
  • 2,040
4 votes

Slow SMTP responses with Exchange 2013 (Not network infra related)

A delay measured in seconds is often a timeout with a request to a third party. So something like a reverse DNS lookup of the incoming IP, or checking against a dead RBL also. You can easily miss this ...
richardb's user avatar
  • 1,256
3 votes
Accepted

Recover deleted mailbox and user- no AD recycle bin

You can't restore the mailbox by restoring the user account. If you don't have a backup of the mailbox then see this link: https://technet.microsoft.com/en-us/library/jj863438(v=exchg.150).aspx You ...
joeqwerty's user avatar
  • 111k
3 votes

Good idea? Refuse incoming emails with our own domain ending? (because they must be fake)

Maybe, but there are some cases you need to consider before you make such a change. 1) Does anybody in your company use any kind of external service (for example Survey Monkey, Constant Contact, etc.)...
David Gelhar's user avatar
3 votes

How to create a script for Exchange Powershell to modify settings for all shared mailboxes?

Use Get-Mailbox, pass the result to Set-Mailbox. Here's a oneliner Get-Mailbox -Filter { <put your filter here> } | % { Set-Mailbox -MessageCopyForSentAsEnabled $True -...
Jeter-work's user avatar
3 votes
Accepted

Running Exchange Powershell script from a batch file: command doesn't work. What's wrong with my syntax?

Try this (added dotsourcing of the second script): PowerShell.exe -noexit -command ". 'C:\Program Files\Microsoft\Exchange Server\V15\bin\RemoteExchange.ps1'; Connect-ExchangeServer -auto; . 'C:\...
Anton Krouglov's user avatar
3 votes
Accepted

AutoDiscover with multiple accepted domains

SRV record or HTTP redirect is the way to go here. For the SRV record, you need to ensure that Autodiscover.example.com does NOT resolve. That will mean checking there is no wildcard in the domain, ...
Sembee's user avatar
  • 2,884
3 votes

How does Exchange handle SSL certificates?

You cannot have multiple certificates for all services. However for Receive Connectors it uses a match on the FQDN. Therefore if you set the FQDN to mail.example.com then you need to have an SSL ...
Sembee's user avatar
  • 2,884
3 votes
Accepted

When integrity of an Exchange 2013 mailbox database is questionable, is it safe to simply "move" the mailboxes, or do they have to be exported?

There is no size limit for mailboxes with the New-MoveRequest command. I would highly recommend using this tool before trying to perform an export/import of PSTs. Move requests are very simple, and ...
Sam Erde's user avatar
  • 3,469
3 votes
Accepted

On-premises mailboxes cannot receive emails from 365 Hybrid deployment

According to your description, if the user login Office 365 OWA, he can see the email, we could know that the mail flow is working fine. And now this issue we need to confirm is the type of mail flow, ...
Jayce's user avatar
  • 824
3 votes

Blocking recurring meetings for Room Mailbox

AllowRecurringMeetings : True Have you tried setting this to False? Set-CalendarProcessing -AllowRecurringMeetings The AllowRecurringMeetings parameter specifies whether to allow recurring ...
Esa Jokinen's user avatar
  • 50.1k
3 votes

Calculate size difference between two Exchange mailboxes

TotalItemSize is not a number, the property has two members: [PS] C:\Windows\system32>(Get-MailboxStatistics administrator).totalitemsize IsUnlimited Value ----------- ----- False 690.4 KB (...
Gert Jan Kraaijeveld's user avatar
3 votes
Accepted

What's a reasonable max number of users I should put in a mail-enabled security group?

Not for most organizations, and 3,000 isn't enough to cause problems. Prior to Active Directory 2003, when a member was added/removed to/from a group the entire group membership was re-replicated. ...
Greg Askew's user avatar
  • 36.9k
3 votes
Accepted

Using EWS to access O365 mailbox

Do you deploy hybrid? Or just sync via AAD connect? Do you deploy ADFS? Browse to https://testconnectivity.microsoft.com. This is a Microsoft-owned tool. If using Office 365, click on the Office 365 ...
Jayce's user avatar
  • 824
2 votes

Good idea? Refuse incoming emails with our own domain ending? (because they must be fake)

You can do this in PowerShell by updating your Receive Connector permissions to exclude Anonymous users from sending as an authoritative domain sender: Get-ReceiveConnector <identity> | Remove-...
Neil's user avatar
  • 248
2 votes
Accepted

How to create a script for Exchange Powershell to modify settings for all shared mailboxes?

To get all the shared mailboxes in your environment, use: Get-Mailbox -RecipientTypeDetails SharedMailbox Running those commands against the results from this command should be trivial.
HopelessN00b's user avatar
2 votes

exchange 2013 email address policy SMTP blank screen

The solution eventually was to use IE to add the policy.
Pieter Houwen's user avatar
2 votes

Unknown ActiveSync Device keeps locking account out

Set ActiveSync to quarantine. That will stop it from synchronising. Then get the user to find the device they are obviously no longer using and remove their account. A more evil answer would be to ...
Sembee's user avatar
  • 2,884
2 votes

Upgrade Win 2012 R2 VM to win server 2016 breaks Exchange 2013

I am glad you said this was a dev environment, otherwise this is a résumé generating event. You have made a number of assumptions with no backing, not even past history of Microsoft to back them up, ...
Sembee's user avatar
  • 2,884

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