Office365 - message to sender for all mailboxes

[timbo343]

Is there a way on Office365 Exchange to make the following work:

- If the sender is outside the organisation

- Send a message to sender informing that @olddomain.co.uk change to @newdomain.co.uk

- Still deliver the message to the receiptants mailbox on @oldomain.co.uk as the mailbox will have a forwarder on pointing to the mailbox on the @newdomain.co.uk

 

I'm trying to cover all avenues here.

[ShellfishClive]

You could put an out of office for everyone that emails from outside the organisation.

 

You'll have to connect to your Office 365 via Powershell get all the mailboxes and loop the usernames to do this on mass.

 

Set-MailboxAutoReplyConfiguration -Identity "s.clive" -ExternalMessage "Sorry please email...put your message here."

 

Something like this should do it:

 

[font=Monaco]$UserCredential[/font][font=Monaco]=[/font][font=Monaco]Get-Credential
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
Import-PSSession $Session -DisableNameChecking
$mbNames = Get-Mailbox | Name
foreach($mbName in $mbNames){    Set-MailboxAutoReplyConfiguration -Identity $mbName -ExternalMessage "This is your message." -AutoReplyState Enabled -EndTime "25/12/2019 9:00 PM"[/font][font=Monaco]}
[/font]

Edited November 28, 2019 by ShellfishClive

[MYK-IT]

Mail Flow Rule.

The Sender is located... - Outside the organisation

A recipient's domain is... - olddomain.co.uk

 

Then gets a bit awkward, as no reply options! (Not sure that the 'Notify Sender with a Policy Tip..' will work!)

 

Perhaps, Block the message... - reject the message and include an explanation (e.g. use @newdomain.co.uk)

 

My Flows

Not used My Flows myself, but perhaps use a variation of this guide? (https://quickclix.wordpress.com/2018/03/25/auto-respond-to-emails-using-flow-in-office-365/)

[timbo343]

Thank you both. I think looping through each mailbox is going to be the best way.

 

I did look at the Mail Flow Rule that @MYK-IT suggested however i'd still like existing @olddomain to be sent through as we have that many systems inplace we struggle to get round them all in time so creating a forwarder for all users gives us that breathing room to change all the online accounts.

 

I honestly knew it was going to be complicated to change email domains but this is just taking the michael whilst having @olddomain inplace just as a backup.

[timbo343]

Just want to come back to this mail rule to expand on what @ShellfishClive has posted.

 

Would this only affect any legitimate emails that are sent to the user's email address as i guess the rule is set on everyone's mailbox box rather than a mail rule which is sat at the edge of the system?

 

I had a thought early this morning if this rule is set, any spam emails that are sent to the user's email address are still caught by the Office365 Spam threat system and the sender of these emails won't receive the automatic reply as the system has dealt with the email first before it lands in the user's mailbox. I'm not wanting the spammer to have the new email domain - if that makes sense.

 

Hope that actually makes sense - to me it's come out clear as mud

[ShellfishClive]

Just want to come back to this mail rule to expand on what @ShellfishClive has posted.

 

Would this only affect any legitimate emails that are sent to the user's email address as i guess the rule is set on everyone's mailbox box rather than a mail rule which is sat at the edge of the system?

 

I had a thought early this morning if this rule is set, any spam emails that are sent to the user's email address are still caught by the Office365 Spam threat system and the sender of these emails won't receive the automatic reply as the system has dealt with the email first before it lands in the user's mailbox. I'm not wanting the spammer to have the new email domain - if that makes sense.

 

Hope that actually makes sense - to me it's come out clear as mud

 

I can't give you a 100% answer on this as am I not to sure, my best guess would be it will only affect emails that make it into the inbox. If you have a spam filter that stops spam emails getting to the inbox then I would assume it doesn't forward it on.

[djm968]

Is not possible to update the DNS records for the old domain to point to the mailbox location of the new domain and set the old domain as an alias on the mailboxes?

[timbo343]

It would but i'm prefering to keep my old domain setup with GSuite and Office365 - I know it's a bit "a**e about face"