- Avoid using all capitals in your subject and body unnecessarily.
- Avoid using punctuation in the subject.
- Avoid using excessive punctuation in the body, eg. punctuation??!!
- Avoid substituting letters with numbers, eg. w3b h0sting
- Avoid having gaps between the letters in words, eg. l e t t e r s
- Avoid using many different font colours in your email.
- Avoid using large font sizes.
- Avoid using gimmicky words or phrases that are commonly found in spam emails, eg: Click Here, Buy Now, As Seen On, Money Making, Get Paid, Make Cash, Pre-Approved, Hot Deal, Satisfaction Guaranteed, Lowest Prices, Save Big etc.
- Include a text version of your email if you are sending an email in HTML format.
- Maintain a good text to image ratio, ie. for every image include at least two lines of text.
- Ensure that your internet IP address assigned to you by your Internet Service Provider is not listed on a spam blacklist.
- Add an accurate SPF or DKIM DNS record to your domain.
- Avoid using shortened URLs (web links) in your email body, eg. bit.ly or goo.gl
- Avoid adding a large number of URLs (web links) to the email body.
- Avoid using rude language or poor spelling.
Even if you do follow the above best practices, there may still be a chance that an email you have sent ends up in the recipient’s junk or spam folder. Spam filter administrators do not publicise their filtering techniques in a bid to stop spammers from circumventing spam filtering.
It is therefore advisable that if you do not receive a response within the expected time frame to follow up with the recipient via alternate means to confirm receipt of your email.