Getting your email past the spam filters

Sender authentication and reputation are the critical factors in the filtering used by ISPs. But there is one final set of hurdles for your emails to navigate.

ISPs may also apply content filters to emails they have accepted, rating an email using various criteria to apply a ‘spam score’.

Passing these filters can mean the difference between your email being delivered into the Junk Folder or the Inbox.

It’s important to ensure you follow best practice when collecting and managing your data and in creating your email templates and content.

Following best practice means that inbox delivery is easily within your reach.

To help you with this, here are some easy do’s and don’ts to follow.

It’s not an exhaustive list as this is not an exact science and different spam filters, firewalls, and ISPs may use different, often changing criteria to filter by content.


Do get a professionally designed template

A professionally designed email with the correct HTML code will ensure your email looks its best in all browsers. Bad coding can attract a higher spam score.

Make sure your email doesn’t have any missing or redundant code

Missing and redundant code in your emails will cause rendering problems and indicates to ISPs that your email may not be professional.

Empty font tags or lots of ‘&nbsp’ for example can damage your deliverability into inboxes.

Send a multipart email

And make sure that your plain text version matches your HTML version as closely as possible.

By sending multipart, even if your recipient is opening on a Blackberry or PDA, they will still be able to view your email.

Check and double check your email for spelling mistakes and typos

Bad grammar and spelling mistakes are attributes of spammers -avoid at all cost, use a spell check but also send tests to colleagues to double check for spelling mistakes as part of your sign-off process.

Use a good balance of text and images

Try to get a good balance of text and images and avoid image heavy emails. Single image emails (i.e. one image – no text) should be avoided entirely.

Personalise properly or not at all

Make sure your database is accurate and allows for accurate personalisation.

Unpersonalised or badly personalised emails may attract damaging unsubscribes or spam complaints.


Don’t use italics and very large fonts

Italics and large fonts increase your spam score.

You can replace large text and titles with images, remembering to keep a good balance between text and images.

Don’t use different fonts and WORDS ALL IN UPPERCASE

Or even worse, gappy text which tries to fool spam checkers e.g. free m o r t g a g e!

Don’t use white text on a graphical background

Spammers often use white text to add content that’s not seen by the recipient to try and pass email content filters.

Use white text on a background colour sparingly and make sure any colour text on a colour background has a strong contrast.

Don’t embed images

Spammers send emails with images as attachments or embedded within the email.

To avoid this host your images online, either through your image library or on your website.

Avoid using forms in the email itself

Forms send submitted information back to a server. No major email programs support forms, and including one might make you look spammy – you should include a link to a form hosted on your website or a microsite.

And of course, avoid words which have a high Spam score

The email copy in your emails is very important and all content filters will scan and mark the words you use in your email.

Some words on their own can cause serious spam implications, or words in conjunction with others can score highly.

We all know the obvious spam words, such as Free, Viagra, Nigeria, Porn, Gamble, but don’t forget that words which go with them such as replica, quality, enhanced, hard, stamina, college, diploma and improve will also score.

Remember the more times you use a word, the higher the spam score. Your spam score is an amalgamation of several criteria so the odd single use of some words may not automatically cause your email to be classed as spam.

Phrases to avoid:

  • No obligation
  • Click here or click below
  • Click to be removed
  • No risk, low risk, risk free
  • Order now
  • Money back guarantee
  • Have you been turned down
  • Spam or Spam legislation

Use a Spam Checker

We recommend running your email through a spam checker that will tell you if your email will be considered spam or not.

It should also show you any broken HTML and which words within your email content score highly as Spam words, allowing you to alter your copy before you send your email.

You should also set up test accounts at commonly used email sites such as Hotmail, Yahoo and AOL to see if your email comes through into the inbox or the spam box.

dotMailer includes a spam checker, an advanced spam checker and Inbox Preview in its email marketing packages. logo

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