Nobody likes spam, and nobody likes having legitimate emails suspended as spam, yet spam is a recurring issue with email, making spam filters an everyday part of the process. Few would use email if spam filters were not in place and highly effective. Also, there are existing laws in place that require that companies act responsibly in this regard.
There are a variety of definitions of spam, ranging all the way from unsolicited bulk email to individual emails that arrived in a questionable fashion. Companies that are less than professional with your email address might sell them to a list service, of which there are many. Or a lone emailer might be abusing one of the free email accounts that are offered by Gmail, Yahoo, Outlook, Hotmail, etc.
How spam is detected in Zendesk Support
Zendesk Support uses one of the most respected spam filter services in the world, known as Cloudmark . While we have no direct insight into their algorithms (which keeps their process safe and secure), we are given some information in the form of encoded "fingerprints" which we can then use to examine the nature of the suspension.
You, as a Zendesk Support customer, can participate in the process also just by recovering an email from your suspended queue . Doing this sends a coded message back to Cloudmark letting them know that you believe the email to be legitimate. Depending on the cause for the spam rating this can resolve the issue for you over time, often just after a few recoveries. This allows for better results through dynamic analysis.
A sudden increase in suspended tickets for being detected as spam can cause you to feel that something has changed on Zendesk Support's side. While Cloudmark is a self-correcting mechanism its ratings can also change quickly to account for a number of factors that might be beyond your control.
A common question, particularly in a forwarding situation, is "Why doesn't Gmail recognize it as spam, but you do?" Gmail's algorithms are among the best in the world and are somewhat customized just to your usage patterns. They are designed to be permissive, particularly to emails that you have responded to from within that account, which is a thing that Cloudmark can not possibly know as there is a more tenuous relationship between the sender, your forwarding domain, and Zendesk Support, as well as Cloudmark's ability to document those historical relationships.
Reasons for suspension
Here are just a few common causes for suspensions:
- A handful of end-users marked your outbound emails as spam.
- Your domain becomes temporarily blacklisted, possibly due to a pro-active outbound marketing campaign.
- Your email forwarding IP is part of a shared-hosting setup like GoDaddy, and this rating has nothing at all to do with you.
- The sender's email address is recognized as a producer of spam.
- The email was generated by an online form, like a php, which is associated with spammy practices.
- Your newsletters do not require a "double opt-in" that sends a confirmation email ensuring that the users want your weekly or monthly mailouts.
- Your attachments included suffixes many filters will act upon, such as .exe, .avi, .swf, .zip, etc.
- Poorly formatted HTML is a hallmark of spam, sometimes the result of converting an MS Word file to HTML.
- Excessive use of bright colors, fonts, sizes, images, etc.
- Having words like free, sex, Viagra, timeshare, buy now, urgent matter, medical breakthrough, money back guarantee, !!!!!!, etc. Even excessive use of the word "opportunity" can cause a raising of the rate.
- A sending or relay server is not configured for reverse DNS lookup.
- Bulk emails are sent using the BCC field.
- Signature file links direct only to sales sites.
- Your mailing lists still include users that have clicked your Unsubscribe link (or you don't have an Unsubscribe at all in your marketing emails)
- Your website doesn't let users update their profile details, which results in a lot of bounce-backs. Or, your autoresponder doesn't require confirmation, which allows people to fill your lists with false addresses.
- Even your local physical mailing address can be listed as engaging in questionable business practices or sales
There are more examples, but that covers several of the basics, just to give you an idea of how a cumulative score can add up pretty quickly. Some of these things are easily remedied while others might be out of your control, and the suspension might have nothing at all to do with your practices. Sometimes it is the order in which these things occur in the email that determines their "weight" against the threshold, particularly if an email is relayed through several servers before it gets to you.
Don't panic if you start to get a number of emails in your suspended queue. Try to see if there is a relationship between them—like if they are all being forwarded through your support email address, or if they're coming from an online form—then open a ticket with us if you feel that you have any more questions. We're always happy to take a look and try to give you a better idea of what might be happening.