Sharing custom SpamAssassin Rules

[murgero]

@d19dotca This looks pretty good. I am testing it now

[andreasdueren]

Is there a way to block all mail going to a specific address?

[humptydumpty]

@andreasdueren I wonder if disabling the mailbox would reject incoming mail

[andreasdueren]

@humptydumpty Maybe worth a try. Currently it doesn't exist and is being delivered through the catch-all

[humptydumpty]

@andreasdueren Yeah, I see the limitation with that set up. Also applies to aliases. It would be nice to block an address when spammers get hold of it.

[andreasdueren]

@humptydumpty Just checked, didn't work, reverted to the catch all. Enabling it and creating this filter did do the trick though.

[humptydumpty]

I was just looking at using a "filter" in Roundcube. Similar end result.

Edit: Turns out I got a few of them set up for aliases, so it should work for catch-all addresses too.

BTW, why use a catch-all instead of an alias/wildcard?

[andreasdueren]

@humptydumpty Not my setup so don't ask me for why not alias lol What's the difference between wildcard and catch-all? On a sidenote: some spam might not fill in the "to". Not sure if this is checking for the header content or arriving address

[humptydumpty]

@andreasdueren said in Sharing custom SpamAssassin Rules:

Not sure if this is checking for the header content or arriving address

Good point. One way to find out

I've been transitioning away from aliases to wildcard, mostly for services that I wouldn't be sending mail from. My understanding is that anything to x@yourdomain.com will be fetched by the catch-all, so spammers send emails to see if you have a catch-all inbox or not. With the wildcard method, spammers need to target it specifically for it to work. For instance, you can set up something like:

*services@domain.com
netflixservices@domain.com
googleservices@domain.com
onetimepurchaseservices@domain.com
aldiservices@domain.com
etc..

Use multiple wildcards:
*crapps@
*yourinitials@
*family@
*groups@

and all of these would be "active" without you having to create it beforehand. It comes in handy when you need an email on the fly and want it to be identified with a specific service.

Edit: I've had my FedEx email address get compromised, but it was using a wildcard. In my FedEx account I updated my address by adding a number to the wildcard (fedex5services@domain.com). Then, I created a filter in roundcube for the old fedex address to send all incoming mail to the junk folder. I haven't seen a single address pass-through.

BTW, you can make wildcards less obvious (I believe in security thru obscurity) by abbreviating things, using initials, different languages, wordplay, etc.

https://docs.cloudron.io/email/#mail-aliases

[andreasdueren]

@humptydumpty Oh I didn't know you could use an Asterix for partial wildcards. That's a neat feature

[necrevistonnezr]

@andreasdueren That‘s what I use daily.