hello big mass mailing issue

I see some users sending 1 email but add 1000 recipients to CC or BCC fields
mail server tries to send that copy to all 1000 recipients

How to block such spam ? It there any way to limit max CC and BCC recipients for example to 3 ?

That sounds more like spam. I would set a limit of emails per hour that any domain can send out to something like 200. There is an option for this in tweak settings.

You can also enable "Silently Discard all FormMail-clone requests with a bcc: header in the subject line" which may help.

If somebody is sending out that much email you should also look into securing your email and limiting just who can send out mail from the webserver (if that is how they are sending it).

thank you for your help

Limits of mail per hours is set to 500
"Silently Discard all FormMail-clone requests with a bcc: header in the subject line" is enabled

But still those spammers are sending mail

well maybe there is some setting that could allow to set message timeout ? so lets say to CC messages to 1000 recipients will take a long time so we could cut connection in x minutes

Also I do not believe that there is no any setting to limit recipients count in CC and BCC

I don't know of any way to limit cc/bcc. Is he sending the emails out via pop or a webpage? If you disallow "nobody" from sending email it will help if it is web based. If it is from an email client...why not just cancel his account?

I would suggest finding the spammer then getting rid of him before you are put on any blocklists.

yes he is doing it form email client so it is very easy to catch him..

anyway I just wanted to know if there some BCC and CC limitation. OK thank you for your comments.

You should have some strict policies in place for this, and if they are violated, terminate the accounts. Protect yourself as mentioned but enforce hosting policies as well.