Email deliverability is the email's ability to reach a recipient's inbox. Have you ever wondered, "How do Internet Service Providers (ISPs) know which emails are 'good' and which are 'bad'"?
ISPs like Yahoo, Gmail, AT&T, Comcast, Charter and others have different ways of determining if an email is 'good' or 'bad' and sender reputation plays a big part. Some factors are:
- Blacklists/Blocklists - This is a list of senders that are denied access to the ISP. The list of senders can include a server/IP address or a domain name. Continue reading to understand how senders are added to a blacklist.
- Spam Filtering - Spam filters use a 'spam score' to figure out if an email is junk/spam. Spam filters look at email content, length of email, percentage of text to images, number of recipients, headers, and more to determine if the email looks like spam. Each email sent is assigned a spam score. Email with a score higher than 5 are flagged as spam, which causes the IP address sending the email to be blacklisted. Spam filters are improving but aren't perfect, so there's still a chance that good email is blocked because it seems suspicious.
- Spam Traps - If email is sent to a spam trap, ISPs immediately recognize the IP address as a spammer and get blacklisted. Spam traps are email addresses created by ISPs that are not used publicly. If someone sends email to a spam trap it likely came from a purchased address list. This is why purchasing a list is bad. It's not as common, but a user could possibly hit a spam trap by entering an incorrect email address.
- Complaints - Email that generates a high number of complaints can make email from a specific IP address look bad and affects the IPs reputation. This happens when recipients mark an email as junk/spam. Keep email content relevant to the targeted recipients to avoid being marked as junk/spam.
- Email Sent - Email sent regularly from a particular IP address or a group of the same IP addresses shows good behavior, but email sent through an IP address sporadically damages the reputation of the address with ISPs. NCR Customer Connect uses a group of IP addresses that have different reputation levels. The IP address used to send email is determined by the users list reputation.
- Number of Bounces - A high number of email sent to unknown/invalid email addresses impacts the IPs reputation negatively. These email addresses are also known as bounced addresses.
ISPs look at the IPs reputation first and then the domain name's reputation. When a domain name is authenticated/verified by an ISP it becomes a reliable sender. When sending email through a reliable sender your emails are delivered to the recipient's inbox.
NCR Customer Connect is registered with all major ISPs and is made aware of any emails marked as junk/spam. If someone marks an email as junk/spam we immediately unsubscribe them to keep future email from being blocked. We work hard to maintain a good reputation and remain compliant with industry standards. Learn what you can do to increase deliverability.
Please review these other articles as well, since they may affect deliverability.