VLAN is great for networks to isolate traffic within certain groups or departments only.

is there such a functionality in Exchange? what i do now is i limit the maximum number of recipients and for group emails, only certain people are allowed to use it. it is becoming cumbersome so i thought if something like a "VLAN" for Exchange exist or can be implemented then internal SPAM can be limited or controlled.

I belive not.

VLAN works on layer3, so when it traffic 'hit's' exchange it doesn't care (in terms of routing) where it came from and where it goes. If you want to prevent spam then you have to let exchange handle it, or a filter/firewall.

As commented by Jesper,.

Switch will simply route the traffic from one Vlan to the server Vlan. Routing happens in Layer3

hi,

i'm just using "VLAN" (hence the double quotes) as a reference for the functionality. this filtering where traffic is limited within certain groups is what i'm trying to achieve with Exchange instead of limiting the number of recipients.

if i belong to the HR group, can something in Exchange be configured such that even if i send a mass email to the whole company, only the users in my group will receive it?

If you want to control mass emailing you can reduce the number of recipients per message.
And create groups for each department and give send permission only to group members/required members.

Set-mailbox Set-Mailbox -Identity Testmailbox -recipientlimits 20

This command will limit the number of recipients per message to 20 for Testmailbox.

Get-Mailbox -database Database1 | set-mailbox -recipientlimits 20

This will limit the recipients per message to 20 for all mailboxes in the database1.

Get-Mailbox | set-mailbox -recipientlimits 20

This will limit the entire organization.

Create groups
https://technet.microsoft.com/en-us/library/bb124513(v=exchg.150).aspx

Control sending permission to groups. Check the delivery management section in the below URL
https://technet.microsoft.com/en-us/library/bb124513(v=exchg.150).aspx#deliverymanagement

yes that is what i currently do. however, the number of groups/members to support are getting too much so i am looking for alternatives.