Reducing spam

Spam now accounts for approximately 95% of all email on the Internet and has become a huge problem. Although we filter out at least 80% of this, some junk emails still find their way into the mailbox and there are several ways to reduce these...

Prevention

There are a number of steps you can take to stop your email address becoming known to spammers. These include...

1. Don't reply to spam.
2. Be cautious when using your email address on sites.
3. Use a contact form on your own site instead of your personal email address.
4. Don't foward chain emails.
5. Turn off delivery receipts.

Microsoft have put together some useful tips to help reduce spam which are worth reading.

Spoofed Emails

Bounced emails that you've not sent are an indication that your account has either been hacked OR far more likely, that a spammer is "spoofing" your email address by using a forged sender's address. It is quite common for spammers to forge other people's domain names into the return address headers for the spam emails they're sending out and it's extremely frustrating when YOUR domain is being used for this. Technically, nothing can be done to stop the spammer from sending out the emails in this way and it's extremely easy for them to do this. Luckily, spammers tend to move on to other domains fairly quickly and it's very unusual to find this going on for more than a couple of days.

Although nothing can stop the spammer from sending the emails, it's possible to restrict their delivery by setting up SPF (Sender Framework Policy) on your account. To do this, log into cPanel® and select the "Email Authentication" option. If you are only using our server for sending emails from your domain, tick the "All Entry" box and click the "Enable" button within the SPF section.

WARNING: If you enable SPF with the "All Entry" box ticked, anyone forwarding their emails (for example, from fred@domain-name-here.co.uk to fred-flintstone@gmail.com) will not receive your emails. This is one reason why forwarding emails to 3rd party servers is not recommended.

Email Dictionary Attack

This is where the spammer sends an email to multiple addresses at a single domain in the hope that at least one email will finally get through. If you use the default (catchall) email account to collect email, this allows ALL possible combinations of email addresses to be checked at your domain but also allows a hacker to swamp your mailbox with spam. Not only will you receive more spam but there's also no way to detect such an attack. Using the default account also puts your main cPanel® password at greater risk of becoming known to hackers. If you don't use the default account, our servers can detect email dictionary attacks from the number of failed attempts and ban the sending mail server from sending more email. In turn, this can greatly reduce the amount of spam emails to all addresses at your domain. To stop using the default (catchall) email account, follow the instructions below.

1. Log into the control panel for your account.
2. Go to the Mail section.
3. Click "Email Accounts" and create a personal account (e.g. fred@domain.tld).
4. Go back to the mail section and click "Forwarders". In this section, add any other addresses such as info@, sales@ etc to be forwarded to the personal account you've just set up.
5. Go back to the mail section and click "Default Address".
6. Change the default address to "Discard the email while your server processes it by SMTP time with an error message" so that future emails sent to incorrect addresses won't be accepted.
7. In your mail program - collect email for the last time using the default account and then in the email settings, change your username to the email account you've created (e.g. fred@domain.tld).

Filtering & SpamAssassin

We first reduce the number of spam emails directly sent to our clients by rejecting all emails from blacklisted mail servers. These are servers which have been reported or detected as sending out spam emails. We also reject any emails which don't conform to RFC standards. As such a high percentage of all email is now spam, this helps reduce the amount of junk cluttering up our client's mailboxes.

Our servers have SpamAssassin installed and our servers will reject all emails with a very high spam score. This will cut out obvious junk and is available via the control panel. We recommend that if you're having problems with spam, that you either set your email software to filter for "X-Spam-Status: Yes" within the headers OR use the "Auto-delete Spam" option within SpamAssassin. A score level of 5 is recommended. A lower value will reduce spam but you also greatly risk losing legitimate emails.

On all our cPanel® hosting accounts, there's also the option to filter emails based on keywords. For more information on this, please click here.

Avoid using autoresponders

If you receive any spam, then we recommend that you don't use autoresponders. It's possible that your auto-response will inform the spammer that your email account is active and you'll then be sent even more spam as a result. It's also perhaps a little worrying that you'll also be advertising the fact that you're "on holiday" or "out of the office" to strangers! Many spam emails are sent with a forged reply address of a third party which results in the autoresponse being sent to a complete stranger who has never heard of you. This can result in your autoresponse being reported as spam.