We’ve created our own set of rules to protect the reputation of our clients and their intended recipients. Not only do these rules help us identify spammers, but they also help increase your deliverability and build a strong sending reputation.

Unfortunately, failing to observe these rules could affect your ability to send through and to use our services. In some cases, it can lead to a rate limitation on your emails, or temporary or permanent account suspension.

Defined below are core statistics the Symbolist team references when reviewing email accounts and sending practices. Please familiarize yourself with this chart and work to stay below these acceptable thresholds. Accounts with statistics above these numbers can face account suspension and in some cases, termination and penalties. Prior warning of such actions will be given in all cases unless the risk is deemed to be critical to the security of Symbolist’s infrastructure.

Statistic Thresholds	Acceptable levels*	Additional details
Bounces	≤ 5%	Calculated on the number of messages that have bounced
Unsubscribes	≤ 1.2%	or 1% if unsubs > clicks
Blocks	≤ 30%	Blocks should be ≤ 30%
Spam Complaints	≤ 0.08%	When sending over 1000 but never more than 50 complaints per day
Spamtrap	≤ 1	Spamtrap hits & unjustified abuse complaints

* Symbolist reserves the right to update the parameters of the acceptable sending threshold without prior notice.

Core Statistics defined:

• Bounces – Much like traditional snail mail, when a destination address cannot accept the incoming package and it gets returned to sender, bounced messages are returned to sender because the recipient address is incorrect or inactive.
• Unsubscribes – Recipients that opt out of receiving communication because they no longer want to receive communication. There are a variety of reasons customers choose to unsubscribe; some might be that they’re no longer interested in the content you’re publishing or are overwhelmed with a noisy inbox, or your content wasn’t what they were expecting.
• Blocks – Messages that do not leave Symbolist servers due to a permanent error. These are email addresses that bounced in the past because they are either non-existent or invalid, or previously reported your message as spam. This also includes email addresses that resulted in complaints from recipients or did not pass through Symbolist’s spam filters.
• Spam Complaints – Number of recipients that marked your message as spam.
• Spamtrap Hits – After a certain amount of inactivity, webmail providers turn email addresses into spam traps to catch senders that are using outdated lists or lists purchased, and/or obtained from third-party companies.
• Unjustified Abuse Complaint – When a recipient reports a sender for messaging without their consent.