It is very often that email marketers face delivery problem and seek for best email practices for their campaigns. ISPs use different spam filters to keep their customers' inbox clean. There are no standard rules that all ISPs follow. Each ISP defines their own set of rules and applies new algorithms intelligently to combat spam.
Following best email practices gives you success in delving emails to your customers’ inbox. Here are some of the basic guidelines you have to follow for better email deliverability.
Don’t use email address of public ESP: Some people use email@yahoo.com or email@gmail.com in their “From” address to send campaigns. ISPs spy out on the campaigns that use “from” email address related to free emailing service. One more important point to avoid this is you can’t set SPF and DKIM settings for those domains as you don’t have any control on the DNS management for those domains. A detailed description of these settings is mentioned in the following points.
Configure SPF and DKIM properly: Setting up SPF record for your sending domain gives information that emails are delivering from authorized IP. The purpose of having properly configured SPF record is to avoid forged or phishing activity emails sending with your domain. DKIM is an authentication process to help ISPS that sending email is not tampered before reaching customer’s inbox. Both are very important to give confidence that you are not spammer.
Don’t send single image email: Spam filters don’t love single image emails. They always doubt them as spam. Email with less content gives more chances to be marked as spam. It definitely hurts your deliverability. Best method of creating an email is either to use HTML or text content in the email body.
Check spam score: Before sending email, check spam score of your email content. Good email service providers like MailGoes, give you a tool to check the spam score on your own. We strictly follow SpamAssassin rules to guide senders about the spamming keywords in the campaign body. If at all your overall spam score is more than 5, there are more chances that your email lands into spam.
Send email to double opt-in subscribers: Most marketers don’t follow this rule. Using purchased / acquired email database does not give you any value addition to your campaign. In fact it hurts your deliverability if you combine this list with your actual subscribers list. When people who actually not subscribed to your service start to receive your emails, mostly they mark it as spam. If spam complaints are increasing more than ISP’s defined limit, they deliver your email to spam folder even to your double opt-in subscriber.
Avoid spamtraps: Spamtrap email addresses are specially created by ISPs to identify spammer. These email addresses actually exist but never used for any subscription with any service. Some spamtraps also include inactive email addresses orphaned by ISPs when their customers are not actively using those email addresses for certain time period. Later these are used as spamtraps to catch spammers. It is always best practice to clean your email database before you actually start doing campaign.
Remove unsubscribed and bounced emails addresses: Try to remove these email addresses for your next campaign. Unsubscribe event occurs when your customers don’t show any further interest in receiving your campaigns. Sending email second time or third time irritates receiver and may lead to mark your email as spam. You should honour your customers’ request and exclude them from your list. Hard bounces occur because of non-existent email address. It bounces back immediately every time you send email. There is no use of sending email to the same address again. You should give first priority to remove hard bounces from your list.