Using Gmail to Filter Spam On Existing Mail Accounts

Spam sucks. We all know that. The question is how to stop it. Those of us who use Google’s Gmail have very little spam problem. Google’s spam filtering is VERY good. When I was using Outlook as my mail client, I was using the paid Cloudmark plug-in to defeat spam. It beats the hell out of the built-in spam filtering on ANY mail client. But, since moving to Gmail, my spam problem has been even less than with Cloudmark. And I don’t have to spend a dime for it.

But, what if you don’t want to use a email address? Perhaps you are using an address tied to your own domain name or from your ISP. You might not want to switch. Well, I have good news and no, it doesn’t have to do with my car insurance. But, I did save a boatload of money on my spam problem by switching to Gmail. And I didn’t have to change my email address.

Gmail as a Go-Between

Gmail is not a self-contained, web-based mail service. They have opened it up to POP3 access and, most recently, to IMAP as well. But, that’s the download side of things. What if you already have an email account elsewhere? Well, Gmail also has the ability to log into an EXTERNAL mail account and fetch the email, bringing it into Gmail.

So, how can you use this to filter out your spam?

Get a Gmail account if you don’t already have one. Then, set it up to get email from your external, existing mail account. If you don’t know if you’re going to like this yet, you can tell Gmail to leave the email on your server so that you don’t split your email up among two servers. Now, with your email coming into Gmail, you can enable POP3 or IMAP access on the Gmail account and then point your email client to download email from Gmail. So, what you have is the exact same email, coming from the exact same account, but via Gmail.

And what do you know, all your spam is being filtered out by Gmail in the process!

If you use POP3 access, all the email will be removed from Gmail servers and downloaded to your client. If you use IMAP, your mail client will simply mirror what is on the server – a great option if you want fully portable mail that looks the same regardless of what computer you are using.

The Gotcha

If you happen to have several email accounts, this system might not be perfect for you. While Gmail will allow you to bring in email from more than one external account, once it gets to Gmail it is all in one place. That means that Gmail will act as a funnel, sending all your mail accounts through one single mail account. Likely you can just use filters on the client side to split your mail up according to the address it originally came in on, but if you actually send your different email address to different physical email files, that will be hard to pull off.

Otherwise (and for most of you), this is a very workable, free way to fight spam on your existing email address.


  1. VanguardLH says:

    While it does work to have your Gmail account yank from your other POP account to do additional filtering and then have your local e-mail client yank from your Gmail account, be aware that you have no control over the mail poll interval. Gmail will poll your other POP account at various intervals depending on how often it finds e-mails in that other account. The more mail polls that result in no e-mails retrieved results in lengthening the mail poll. It might start out at 5 minutes for each mail poll after you first add your account to Gmail but this mail poll interval can go up to 50 minutes if Gmail repeatedly sees no e-mails to yank from your other account over successive mail polls. As an example, you might be expecting an e-mail very soon after registering for use of a web site that sends you a confirmation e-mail which you must use to complete the registration process to use that site. You cannot login into that site until you complete their registration process. You keep waiting for their e-mail to show up. Gmail won’t poll your other account for up to 50 minutes and you’re left wondering why you never got their confirmation e-mail. So either you wait or you use the webmail interface to your other account to get at that e-mail now. Using Gmail as a server-side filter to yank from your other POP accounts and using your e-mail client to pull from your Gmail filtering account will result in very long delays in receiving e-mails if you don’t get that many to reset Gmail’s poll interval.

    By the way, you do NOT need to configure your original e-mail account to forward (push) to Gmail. If it has POP access, you can configure Gmail to pull your e-mails from your original account. So you can push or pull to your Gmail account.

    Since Gmail accounts are free, create a new one for each original account from which you yank and use Gmail for additional filtering. If you have N accounts, create N Gmail accounts. Each Gmail account yanks from just one original account. That way, you can track through which original account an e-mail was delivered, and it can help in configuring your e-mail client to use that original e-mail account when you reply to an e-mail that was delivered to it (and then yanked to the matching Gmail account).

  2. Unfortunately gmail’s spam filters aren’t perfect – I get about 6000 messages per month, and most of those are spam….no matter how many times I mark the message as spam I continue to see them in my inbox..

    I would like a spam filter external to gmail.

  3. I tried using Gmail as a go-between spam filterer. It would yank from my POP3 account and I would yank from the Gmail account. I had 6 accounts so I had 6 separate Gmail accounts (so I could differentiate via rules as to which original POP3 account the e-mail got sent based on through which Gmail account it got retrieved). Alas, the ever lengthening mail poll intervals that I mentioned before eliminated using Gmail as a spam filter. It was not a viable option because of the super-long delays in getting e-mails, especially those that I wanted to get now (because I was waiting for them).

    For Todd, I also started getting “replica watches”, “discount shoes”, and other spam through the Gmail accounts. So as Todd mentions, Gmail is not a perfect solution for server-side spam filtering using a free e-mail service. Yes, I could define server-side rules in my Gmail accounts (duplicating those rules in each of them since I had one Gmail account to track from which original POP3 account the e-mail got delivered) but why should I? The point was to eliminate me having to define rules in a never ceasing loop of getting spam, define another filter, get spam, define another filter, and repeat.

    No matter how I’ve tried to use server-side anti-spam solutions using free services, like Gmail, and making sure I don’t get stuck with a provider that likes to pretend they have a unique and 100% filter (which is nothing but another resurrection of the irresponsible challenge-response scheme), I still can’t get away from using my own client-side spam filter, which is still SpamPal. It gives me DNSBLs (DNS blacklists – just don’t use any that are DULs, or dynamic user lists, of dynamic IP addresses since SpamPal checks all headers and most trace back to the sender’s host which is likely to have an dynamic IP address). It also provides Bayesian filtering (a statistical guessing game) which isn’t useful unless you get hundreds of e-mails each week to provide a decent sized profile of historical data that is effective against the short-term spam spewages. The URL body plug-in lets you apply the DNSBLs against URLs in the body of an e-mail since many spammers need to point at their site and some of them operate their own web server on their own domain from which they spewed their spam (so it is not effective against mailer trojans that send spam). SpamPal isn’t perfect, either. You can get false positives and why I use its UserLogfile plug-in to keep a plain-text version of every spam-tagged e-mail (so when my rule deletes it there is still a safe backup copy that I could look at).

    Some ISPs are very weak at spam filtering. My ISP (Comcast) has (or had) very loose filtering so lots of spam slipped through their filter. I have a free AOL e-mail account (using their service so I can pick one with a domain that is NOT but they are also too weak. Not only do they miss a lot of spam (false negatives) but I had a lot of good mails (false positives) stuck in the spam folder that required me to waste time going online to my AOL e-mail account to check the spam folder. So I’m still stuck using SpamPal as a client-side spam filter.

    There are plenty of alternative client-side spam products. Many of them hide they use Bayesian or challenge-response behind a barrage of marketing blitz to hide that they offer nothing unique or new.

  4. I’ve been using gmail as a spam filter, using the double yank as VanguardLH describes, since early July, and so far I’ve found it quite effective. But, I’m now stopping because I suspect the process loses emails. Certainly, since I’ve been using it, emails yanked from the gmail server sometimes show up in my Thunderbird client with the body belonging to the adjacent email; and occasionally an email that I know was sent to me falls into a black hole and seems to be untraceable. I’d rather have to deal with some of the spam manually than have this happen. So, it’s back to a client-side spam filter (any recommendations received with interest).
    btw, yes I know Thunderbird has its own spam filtering, but I believe I’m not the only person who has found it decreasingly effective.

  5. What is captcha code?, pls provide me captcha code codes or plugin, Thanks in advance.

  6. Re my comment of a year ago: I now think the problem wasn’t with gmail but with the interworking of Thunderbird with AVG antivirus.

  7. Reda Ureste says:

    My God, i thought you were going to chip in with some decisive insight at the end there, not leave it with we leave it to you to decide.

  8. Do you know of a way to use Outlook to retrieve mail via gmail, BUT then send mail via our 3rd-party hosted service? The problem is that, after setting up Gmail to grab my email via pop and setting up outlook to grab it from gmail, if I send from outlook, it looks like it’s coming from gmail, not from my company. Even sending from gmail shows my company email, but then also says “on behalf of [email protected]” I want to keep the process opaque so no one knows I’m using gmail. Is this possible with outlook 2007? Or even another mail client?

    • No, the only way around it would be to use your ISP’s STMP server for sending E:Mail, and G:Mail for receiving.

      It does provide excellent spam filtering though :).

      Yours – Antony

  9. I’ve been using gmail to filter spam out of my ISP email account for quite a while now. The delays are not anything I ever noticed to be significant and for a free effective way to remove the hundreds of hundreds of spam messages per day that I was getting in my mail box, I couldn’t have asked for a better way to get rid of unwanted spam.

    Its not perfect but for some people the gmail as an external spam filter is an excellent solution and highly recommended.

Speak Your Mind