Tuesday, April 30, 2013

Limiting the maximum number of recipients per message

In real life there are situations when we need to block message or move all recipients to BCC field if it have too many recipients in TO and CC field. When unaware or simply by mistake user sends a newsletter e-mail to all customers and puts them in TO field, it will be a scratch on company reputation. Or, if you send a job announcement to multiple people, you may want to use BCC to keep the identities of the potential job seekers private.

With Message Recipients Count requirement and Block Message action or Move All Recipients to BCC field action those situations will never happen. This requirement will count recipients per message, user, domain or any other condition based on message properties. See all conditions and exceptions.

Limit the number of TO, CC and BCC recipients
To set restrictions for all, incoming or outgoing messages in Postfix and Sendmail the best way is to choose search in TO and CC field. It will count recipients skipping the BCC field. When number of email addresses are reached the actions will be taken.

Good policy is to block the message and inform sender about the reason why it was blocked. Block Message action have option to customize the message which is delivered to sender.
Define custom reject message while connection.
Better and more elegant way than blocking message is to Move All Recipients to BCC field. It will prevent sharing the e-mail addresses with persons which should not see them.

This action is simple. No options or configurations need to be done.
Prevent recipient names from showing by using Bcc
Keep the recipient list private. Bcc can help you to be respectful of others' privacy by keeping them in the loop without disclosing their identities.

Learn more about policies which can be applied with MSH Traffic Policy to your mail server.