February 15, 2022 / Lily Collins

FastMail Spam Filter – How Does it Work and Everything You Want to Know

Constantly been troubled with unwanted messages in your inbox? You have got to look for the best spam filter from your email service provider. A spam filter is an indispensable tool for an individual or company. As per studies, more than half of your emails that you receive in a day are classified as spam or junk. Fortunate are those who are using the Fastmail email service. Fastmail spam filter customizes your needs. The robust spam filter prevents spam emails from reaching out to the Fastmail servers. The remaining spam messages are further caught and field into Spam.

Read on to know everything about Fastmail spam filter – custom spam protection settings, spam checking process, forwarding hosts, trusted hosts, and spam-check headers.

Table of Contents

Want to Control Fastmail Spam Filter? Check Spam Protection Settings

Go to the “Settings – Filters & Rules” screen and click on “Advanced options”. This bestows complete control over when messages are delivered to your Spam folder or discarded immediately before you could see them. So, how’s it determined?

Spam Score! Yes, every message that you receive gets a spam score, which shows how likely the email is to be spam. Simply, you need to enable “Fighting Spam”. This will report the message as spam.

How to Improve Spam Protection in Fastmail?

There are several ways that Fastmail improves its spam protection. To reduce spam, it allows you to report spam, adjust Fastmail settings, report spam via an email client, sending via external servers, and avoid using forwarding services. Further, it identifies legitimate emails by checking the spam scores, marking folders as non-spam, marking mails as non-spam, and adding known senders to the contact list.

How to Check Spam – The Spam Checking Process

How does the spam checking process take place? Fastmail carries out a myriad of steps or checks (SMTP checks) to ward off any spam message. Although the checks are professionally done, certain emails manage to sneak in, hence creating trouble for users. To check the received emails (based on the content of the email), Fastmail performs many checks to determine if the emails are spam. The emails are analyzed using SpamAssassin, which further gives a spam score. The most popular checks that SpamAssassin does include –

Content filter
Bayes database
Razor
DNSBL
Header and body checks
Structure

How to Improve Your Fastmail Spam Filtering?

Follow the steps below to improve your Fastmail spam filtering in your account.

Consider turning on Advanced Spam Filtering:

Go to the screen “Options -> Spam/ Virus protection”.
Based on your subscription, switch from ‘Basic’ to ‘Normal’, ‘Aggressive’, or ‘Custom’ level filtering.

Don’t Use Forwarding Services: You should avoid using forwarding services. If you do it from an old account, tell people to use these addresses – @fastmail.fm or @sent.com, etc.
Report Spam and Non-Spam Emails: Another effective way to improve your Fastmail spam filtering is to report spam and non-spam emails.

Reporting more than 200 spam and 200 non-spam messages will activate your personal bayes database. This eventually increases the scoring accuracy of the spam filter in your account.
Setup auto-reporting on folders if you use IMAP mostly. Log in and go to “Options”, and then navigate to “Folders”. Set the property on folders as “Learn as non-spam”. Now, create a folder called “Learn spam”. Go to your IMAP client, get those spam emails, and transport them to the respective folders.

Save Known Senders: If you are regularly receiving emails from your clients or known people, add their email addresses to your known sender address book.

Why Do You Get So Much Spam?

One of the primary reasons spam messages pour into your inbox is through automated servers. The higher the incoming messages, the more the chances of spam in your mailbox. Here are the ways through which spammers catch hold of email addresses.

Address Lists Stolen from Servers
Purchased Lists
Contact Lists Stolen from Systems Infected with Viruses
Common Words or Names
Random and “Dictionary” Attacks