Forum Discussion
Detecting or avoiding mass/bulk mail messages
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/exchange-online-limits#sending-limits-across-office-365-options
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.
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..)
