There are two main reasons for a message to be delivered to the SPAM or JUNK folder instead of the Inbox:
- The content of the message
- Your reputation as a sender
Message Content
There may be something in the message that is triggering one or more "red flags". There are many factors at play. Antispam filters use many content- and structure-related parameters to decide whether a message is delivered to the INBOX or the junk folder.
The first thing to do is to ensure that the message was written and structured correctly. To this extent, please see our
guide to creating good HTML email messages.
On our Web site there are other resources that can help you write messages that avoid raising "red flags" with antispam filters. In addition, from within your administration console, you can use the E-mail Check-up feature (and the Spam Check optional feature) to perform an automated check on the message.
Also note that some of the reasons that may cause the delivery of your message in the junk folder may seem rather trivial. For example:
- You are using text with characters repeated multiple times (xxxxxxxxx)
- You are using a "no-reply" sender address. Is always better to encourage the recipients to answer and to manage these answers.
Sender Reputation
Your reputation as a sender is determined by many different factors. Different ISPs (the Internet Service Providers that "receive" your emails, such as Gmail, Yahoo! Mail, etc.) use different combinations of the following factors to determine your reputation as a sender, over time:
- Number of SPAM complaints filed by recipients of your messages
- Level of engagement of your recipients (open rate, click rate, etc.). It is very important that you only send messages to active users, and reduce to a minimum messages that are sent to users that are typically inactive.
- Recipient reputation: are you sending messages to recipients that receive a lot of SPAM? The idea behind recipient reputation is that if a recipient attracts a lot of spam, and that recipient is also in your list, your message is more likely to be spam (note: this factor is just one of many used in the algorithms that ISPs use to determine whether a message is spam or not).
- Whether your sending domain (the domain name of your FROM address) has been blocked by blacklists such as Spamhaus (http://www.spamhaus.org/lookup/). To check to see if your sending domain has been blacklisted, you can use a service such as: http://domain-blacklist.e-dns.org/
- The reputation of your Email Service Provider, such as MailUp. Specifically, the reputation of the IP addresses from which your messages are sent. Professional ESPs have long-term, ongoing relationships with all major ISPs to ensure that they maintain a reputation that is as high as possible (e.g. by immediately handling spam complaints and bounces). Typically, your messages are sent from IP addresses that are shared with other senders. You can also request that dedicated IP addresses be used for your account, for an additional fee.
Article ID: 324, Created On: 8/8/2011, Modified: 5/9/2012