Category Archives: Geek

Filtering Out Mobile Spam

I don’t know if you can do this with a Windows PC, as I dumped that failed proprietary computer operating system long ago in favor of Linux. With a Linux PC and either your own mail server or a friendly Internet service provider, I’ve found that you can cobble together a system that so far has removed 100% of the spam email from my mobile phone.

This was a big deal to me, as I have multiple email accounts and use email heavily to get things done. On my desktop, I run a Linux email client program called Claws Mail, which is pretty great once its set up properly. It comes with two different spam filtering systems, one of which catches probably 90% of the spam sent my way.

But until very recently, I was snowed under with spam when checking my email accounts via my cell phone. For whatever reason, email apps for the Android operating system (and as far as I know for Apple phones as well) are unable to filter out spam. My spam load was so heavy that it could take me 10 minutes to go through a haystack of email before I found the one needle that was not spam.

Then, I gave it some thought and did this:

First, I created a new email account on my email server, with a name that for this post I’ll call Then, I went in to my phone’s email app, K-9 Mail, and removed all five of the email accounts I’d been monitoring. Then I added a single account to the phone –

This next part took some time, but to me it was worth it. In my desktop email client, Claws Mail, I have the ability to “filter” email messages according to a variety of conditions, such as who a message is from, who it is to, what the subject is, etc. I can have Claws Mail move certain messages to certain “mailboxes” to keep related messages or, say, family email, separate from the rest.

It turns out Claws Mail also can forward or redirect any email, based on the conditions above. This was the key to my system.

I set up my email filter rules so that any email from certain senders whom I consider important will be redirected to my account. Thus, if my wife or one of my kids, or other relatives, or my friends, or contractors or business partners sends me an email, I will still get it on my phone. Voicemail also gets through to the phone, as do text messages.

But the spam crap that makes up probably 97% of my total email volume cannot get through to my cell phone. Instead, it is filtered into the spambox on my desktop computer.

The system isn’t perfect. On occasion I will get a legitimate email message from someone whom I never have met before, and such email will not make it to my phone. Really that’s not such a big deal, as I can answer that mail when I get home.

The biggest flaw in this new system probably is the fact that it won’t work unless I keep my home computer up and running all the time when I’m away. This can leave my computer vulnerable to thunder storms, which is a consideration I need to ponder.

But otherwise, the spam-load this has taken off of my phone is pretty impressive.

Also posted in Communications