Blocking Email Spam

[natzilla]

Hi

I've been seeing these coming in for a while now, and I have put in rules to block these from coming in, but I think my wildcards are not working. Is there a better way to do this?
file:///home/pfs/Pictures/Screenshot%20from%202023-05-30%2011-19-17.png

[jdaviescoates]

@natzilla I've not had big enough spam issues to bother trying this myself yet, but I recommend taking a look at this post and thread by @d19dotca

https://forum.cloudron.io/post/58922

See also the docs:

https://docs.cloudron.io/email/#custom-spam-filtering-rules

[ccfu]

@natzilla
We have seen these on our mail server over the past few weeks as well, in fact they stopped yesterday and started again this afternoon. It appears a botnet is sending out thousands of mails to random addresses, mostly from senders with .ru, and .cz but the majority are in fact being sent out from compromised computers with (dynamic) IPs in India, Argentina, Brazil and China. The spam filter blocklist will not have any effect on these as the mails are already being rejected because there are no valid recipients as you can see in the event log. Just ignore them and eventually they will stop. If by chance a recipient address happens to be valid there is a very good chance the IP will be blacklisted anyway or, if not, the mail with have a high spam score.

[natzilla]

@ccfu Ok, I've just trying to be proactive but if it's not such a bad thing currently then that is fine with me. I run one for a relative and I don't want them to freak out about spam emails if it happens to come in. haha

Ideally I would just block everything out of country since nothing will be applicable for the email I am in charge of. Don't know if that is possible or not.

[ccfu]

@natzilla Your wildcards should work if a mail from one of those country TLDs actually makes it as far as a user's mailbox. The mailserver automatically rejects a lot of spam already, for example if the sending IP is on a blocklist listed under DNSBL Zones on the email page.

[natzilla]

@ccfu oooh ok. The list won't become active until it hits a real box. Ok, that makes a lot more sense now. I appreciate it.