General Help
1) Don't publish your business email address anywhere public on the internet (e.g. on Facebook) - spammers will harvest it!
2) Your website should use a proper "Contact Us" form with an anti-spam CAPTCHA or similar measure - do not be tempted to simply write your email address on your webpage! Spammers harvest email addresses automatically.
3) Never reply to a spam email - it will reveal that your email address is active.
4) Don't send out bulk emails from your business address - use an email marketing tool which can help control where the email goes.
5) Use a "throw-away" email address wherever possible when signing up to websites, forums or other internet registration pages. (you can easily use a gmail email for these).
6) Consider turning off commenting capabilities on your website, if you are receiving lots of comment spam.
Using Gmail or Google Apps
If you are using Gmail in conjunction with Purple Dog, it will certainly assist in controlling spam because Gmail does have an advanced "community driven" spam filter. It is a very good idea to check the Gmail "spam" folder each day to ensure genuine emails are not being caught. Also, when you do receive spam in your gmail inbox, marking it as such will to help reinforce the Gmail community spam filters. If it is Phishing email (e.g. it looks like an email from Trademe, or your Bank, but hovering over the links (do not click them) reveals that the actual URL is a spam link), ensure that you mark it as such.
If you are using Gmail in conjunction with e.g. Outlook or other desktop email programme, it's a good idea to check your settings to make sure the email programme is not downloading the Gmail spam folder.
Check your email account settings in cPanel
It is worth reviewing your email account setting to ensure that they are set or updated correctly. In particular, it is worth checking in cPanel to see if you are using a "catch-all" or default email address. The default e-mail address - if activated - will "catch" any mail that is sent to an invalid or non-existent e-mail address at your domain. Thus, any email sent to the non-existent address will be forwarded to the default email address that's been entered.
If you are using a catch all or default email, this means that you will receive all emails sent to your domain, regardless of whether anyone actually exists at that address or not. Whilst this may be fine for a short transition period (for example, when you've changed email addresses or domains), in general it is recommended to reject such unrouted email that were sent to an unknown address - otherwise, if spammers target your domain, and you forward mail to a default address, that address is likely to receive a large amount of spam.
By rejecting unrouted emails, the sender will receive an "undeliverable - No such person at this address" message (defeating any spammers) and any authentic users will usually try to contact you another way e.g. using your phone number, or perhaps your website contact form to confirm your real address.
You can check or change / set this option in your cPanel under Email Management Tools > Default Email Account (see screenshot below). If you need help with logging into cPanel, you can view the login to cPanel help article.
Using cPanel's Spam Filter
Your Purple Dog webhosting control panel - cPanel - offers a powerful software called Spam Assassin. This is by default disabled because it does require some time and effort to make sure it is working accurately. Although it is easy to activate it, you should monitor it carefully to tweak the settings as necessary, to ensure that spam is correctly being caught, rather than authentic emails.
To use Spam Assasin, first login to cPanel, then navigate to the Email section and click on Spam Assassin (see screenshot);
Next, simply click on Enable to start Spam Assassin, as shown:
Automatically Delete Spam
If you wish, you may elect to enable Automatically Delete Spam. This function automatically deletes messages that meet or exceed the score limit. Activate this function by clicking the Auto-Delete Spam button under the Filters heading. Click the Disable Auto-Delete Spam button to disable this feature.
Note: Enabling this feature could cause you to lose email that is not spam, if a message meets or exceeds the defined score. Make sure SpamAssassin is configured properly for your account before using this feature. We recommend that you use Spam Assassin for at least one week WITHOUT automatically deleting messages, so that you can monitor the activity and feel safe that it is working accurately.
SpamAssassin examines every email message for spam characteristics, then assigns it an overall score. Enter the score required for a message to be considered spam. 5.0 is the default setting, and is aggressive. It would be suitable for a single user, but it is recommended that you should set the default to be more lenient (8.0 or 10.0) to begin with, then reduce down to eliminate more spam as required.
Add Addresses to the Blacklist
You can add addresses to the SpamAssasin blacklist to block the receipt of emails from any address that is obviously spam.
When you add the addresses to the blacklist, use * as a wildcard to represent multiple characters and ? to represent a single-character wildcard.
The following examples demonstrate how to properly use wildcards in the blacklist:
[email protected] — Blacklists a single email address.
*@example.com — Blacklists all the addresses at example.com domain.
[email protected] — For example, [email protected] would be blacklisted, but [email protected] would not be blacklisted.
If you need to add more than 5 addresses to the blacklist, fill in the first 5 text boxes and click Save. Additional text boxes will appear.
Add Addresses to the Whitelist
Equally, you may wish to make sure certain emails are never marked as spam. You can enter addresses whose email is often blocked, but from whom you wish to receive email.
You may use * as a wildcard for multiple characters, or ? as a single-character wildcard.
[email protected] — Whitelists a single email address.
*@example.com — Whitelists all the email addresses at example.com.
[email protected] — For example, [email protected] would be added to the whitelist while [email protected] would not be added.
By default, 5 text boxes appear, allowing you to add 5 addresses. To add more than 5 addresses:
Fill in the first 5 text boxes.
Click Save.
When you return to the page, more text boxes will appear.
For more information on setting up and using SpamAssassin, you can consult the cPanel help page here: http://docs.cpanel.net/twiki/bin/view/AllDocumentation/CpanelDocs/SpamAssassin
If you find that none of the above helps you, there are more agressive measures that can be used, so please open a support ticket so that we can assist you.