Detecting or avoiding mass/bulk mail messages

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New Contributor

Detecting or avoiding mass/bulk mail messages

 

From time to time, we have in our Office365 environment, some internal AND external users, sending mail messages to 200 recipients, 400 recipients.

So, some people asked me:

 

1) There is a way to limit the max number of recipients of a message, like, 30, 50 or 100?

 

2) There is a way to build a rule, counting the number of recipients, and when someone send a message to, let´s say, 30, 50 100 recipients, this message not be delivered? Particularly import for external users

 

3) There is a report, to show me messages sent to more than 30, 50, 100 recipients

 

 

7 Replies
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Hi

1) There is a way to limit the max number of recipients of a message, like, 30, 50 or 100?
Yes, you can do that by creating Distribution List for each , (Ex Distribution List 1 with 30 people grouping, Distribution List 2 with 50 etc.,


2) There is a way to build a rule, counting the number of recipients, and when someone send a message to, let´s say, 30, 50 100 recipients, this message not be delivered? Particularly import for external users

you can find the number of users in each distribution list's property that you have created

3) There is a report, to show me messages sent to more than 30, 50, 100 recipients
let me find out where exactly you would collect this data.
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Hi! I believe he’s trying to prohibit spam/bulk mail going out to an extensive amount of people, therefore limit the amount of mails a sender can send at one time! DL is just a group of predetermined addresses
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I might have misunderstood though! Also is this bulk mails legitimate? ( in that way they are sent with purpose of the internal senders )
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I think fborup is referring to communication & Announcement , Thats why I commanded the DL
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Yeah, could be! Just have to wait and see :)
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1) maximum recipients per message is set to 500 in ExO, you cannot change this: https://docs.microsoft.com/en-us/office365/servicedescriptions/exchange-online-service-description/e...

 

2) No. The only way you can do something like this is via custom transport agents, which are not available in ExO

 

3) No. Best you can to is harvest the message trace logs for each message and count the number of recipients there, but I haven't seen a ready-to-use solution that does this.

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Thanks ALL!

 

Yes, i´m not looking into DLs, i´m worried about mass/bulk unsolicited mail.

 

Sometimes end users select hundreds of people and send messages without thinking about the impact, so we would like to limit and block hundreds of people being copied.

 

It will be good to have some granular control in transport rules to, for instance, allow only communications department to send those mass/bulk messages, but denying regular users to do it

 

 

In the past we had some users sending complaints or doing some personal advertisements (crazy..)