How much filtered spam ends up in the junk folder?

[sync00]

I've been using a disposable email address service for many years. So I have no experience with spam filtering.

I'm thinking of getting rid of the DEA service and just using spam filtering. I regularly get valid emails in my Junk folder. I don't want to look through hundreds of spam messages every day looking for valid emails.

Does most spam end up in the Junk folder or does it get bounced? Is there even a way to tell how much spam gets bounced?

[DrStrabismus]

The distinction is between reject and file to junk - hopefully nothing is bounced (backscattered).

It's hard to say how much spam will end-up in your junk folder, and it's likely to change over time. I'd suggest you continue with some form of disposable addresses.

Have you looked into why you are getting legitimate emails in your junk folder? Most such mail should be hitting the BAYES_00 spamassassin rules if you are training properly. Is that happing?

[sync00]

I did some training in the beginning. Then I read that training requires something like 200 emails and I stopped.

[DrStrabismus]

200 is what's required just to turn it on - in the early stages you can get very erratic results.

[sync00]

Since I only get valid email in my junk folder it is only a minor nuisance. I would get motivated to do the training if my situation changes and I start getting spam.

[n5bb]

Here is how Fastmail controls spam:

• As noted before, spam isn't "bounced" (returned to the usually fake sending address) automatically by Fastmail. You can create a rejection reply to the sender in the Options>Define Rules>Reject tab, but since nearly all "random spam" messages have a fake return address this is usually a very bad thing to do.
• There are various ways that spam messages are prevented from appearing in your Fastmail Inbox.
  • Fastmail uses an "insecure sender" feature which rejects incoming connections from email servers which appear to be improper (such as zombie home PC's infected with viruses).
  • If incoming email server connections are not blocked, in some conditions they might be delayed using greylisting. An example might be if someone using their own home email server tries to send you a message.
  • In the Options>Spam/Virus Protection screen you can enable a filter which discards incoming messages which fail a virus scan.
  • In the Options>Spam/Virus Protection screen you can enable automatic spam filtering, and using the Custom settings you can control exactly how the spam filters work. If you choose one of the non-custom setups your spam will be filtered and filed or discarded as described.
  • The spam filter is implemented in the Sieve script which is executed when a new message arrives at your account. The choices in the Spam/Virus Protection screen automatically change your Sieve script -- so don't use a custom Sieve script unless you are willing to manually add the spam filtering features to your script.
  • The most important manner of preventing false positives (good messages appearing in your Junk Mail folder) is the use of address book whitelisting. Incoming messages from addresses in your online Fastmail address book won't be filtered. You can whitelist whole domains with a wildcard -- for example, use *@gmail.com to accept all messages from Gmail. You can only use that construction (*@domain.xxx) or the complete email From address.
  • If you look at the full headers of a received message, you will see that Fastmail uses the SpamAssassin system to create several spam related headers, including the following:
    • X-Spam-hits --This header shows the components of the spam score for a message. For example, it might show that a message passes the Bayes filter with a very low probability of being spam with "BAYES_00 -1.9" (a negative spam score). The "BAYES_USED" tag shows whether the spam filter used global or user Bayes filtering on the message contents. The Bayes filter is a powerful tool for finding messages reported as spam or non-spam by everyone (global) or you (user).
    • X-Spam-known-sender -- This header is set to yes if the sender is known (From address in your online address book). If that address is in any Address Book groups you have set up, those groups will also be shown.
    • X-Spam-score -- This header shows the sum of all X-Spam-hits spam tags, and is used to control spam filtering. If the sum is negative or the X-Spam-known-sender header is set to yes, the X-Spam-score is set to 0.
• So the three things you can do to help the spam filtering work properly are:
  • Add the email addresses of senders you want to accept to your online Address Book.
    • When you read an email you will see the [Add] link at the end of address fields which contain addresses not already in your Address Book. If you click that link you will get to a screen which lets you add those addresses to your Address Book, and lets you specify which group to use.
    • You can also manually add addresses to the Address Book.
  • Mark messages as spam or non-spam, so that your user Bayes filter will get activated.
    • If messages are left in your Junk Mail folder for 24 hours (overnight at the Fastmail servers in New York City) they will automatically be classified as Spam. You can control this daily spam or non-spam automatic classification in the Options>Folders screen. If you set this up properly, you don't have to manually mark messages as spam or not-spam, since if they are moved to folders which are set up properly they will be automatically classified each day.
    • If a message is incorrectly filed (false positive in Junk Mail or spam in Inbox), it's important that you correct this using the Report spam or Report non-spam buttons at the top of the message reading screen. These buttons cause any spam labeling to be corrected and the messages to be moved to the proper folder (Junk Mail or Inbox).
  • Be sure to check the Options>Spam/Virus Protection screen and understand how you have your spam filtering set up. The Custom option gives you full control. At the bottom of the screen you can see your Bayes status. User Bayes filtering will allow your particular spam and non-spam tagging to have a direct affect on your spam filtering.

Bill

[hadaso]

Originally Posted by sync00

Since I only get valid email in my junk folder ...

You can just turn off spam filtering. Turn it back on if you start getting spam regularly. (hopefully that will not happen!)