When you send a single email to a co-worker or friend you can be very confident that they will receive that email. The situation is different when you are sending a bulk marketing email from a platform like TalkBox. This is not because of technical issues in the sending platform but because bulk email can look like spam. There is no obligation for a mail server that receives an email to pass it on to the intended recipient. This is a good thing, if email was to be delivered completely unfiltered the medium would be effectively useless. We would all be swamped with spam and would have a hard time finding the real emails amongst it.
When we talk about 'email deliverability' we're talking about the proportion of emails in a batch that make it to the recipients inbox. In an ideal world, this would be zero for spam and 100% for everything else, we would completely separate the ham from the spam.
Email filtering systems use whatever information they have to try to determine if email is spam or not. This can be more of an art than a science and sometimes they will filter out emails that should be delivered. This is called a ‘false negative’ and means that a good email can be identified as spam and rejected. This article is about what you can do to optimise your email deliverability and reduce false negatives. It all comes down to sending emails that don't look like spam. This involves both technical measures and the content of the email itself.
How not to send spam
There is no definitive way to determine that an email is spam. This is inherent in the problem, spammers try to make their emails look like legitimate emails. As spam becomes more sophisticated so must the email filters, it's an arms race. However, while the set of spam characteristics can change there are some basic things you should do to optimise your deliverability.
The content of the email
There are certain things that you can include in the text an email that will make it look like spam. This is because spam filters will compare new emails to others that have previously been reported as spam. These characteristics are dynamic so it comes down to using common sense. Some examples of what not to say are
- Order now
- Meet singles
- Earn cash
- Reverse baldness
- I may not know you, I believe you were chosen by God to receive my cash grant donation of $2,000,000 USD.
If you think your subject line or content sounds ‘spammy’ you should probably reword it or even rethink your approach to email marketing. It’s a good idea to think of your emails as providing information to engage your subscribers rather than constructing advertisements which are delivered by email. Digital junk mail is still junk mail.
The links in your email can also make it look like spam. We recommend that you do not use link shorteners such as bit.ly, these can be used by spammers to hide the target of a link.
We recommend that you don’t send image only emails, or emails that have a high link to text ratio. Also, it’s a good idea to proofread your emails, as poor spelling and punctuation are spam characteristics.
Spoofed server addresses
Spammers try to make their emails look legitimate by faking the “From” address. For example, a spam email might have a from address of ‘email@example.com’ however this email will also have a source IP address that can’t be faked.
Sender Policy Framework (SPF), part of DNS, is a system that lists the servers that are permitted to send emails on behalf of a particular domain. This allows mail filters to compare the source of an email with a list of permitted sources and block emails that have not come from authorised sources.
When sending email from TalkBox you can specify any sender address you like. You could in fact send emails ‘from‘ firstname.lastname@example.org. We strongly recommend that you only send email from a domain that you control and you add the appropriate SPF record to your DNS. This is a way of formally saying that TalkBox is permitted to send emails from your domain. See this article for instructions on how to do this.
All email is sent by an outbound mail server. Your company or email provider will run one for your personal email. TalkBox has a collection of outbound email servers for sending its emails. The address of the sending server is always available to the mail server that receives it. This can’t be faked as it’s inherent in the protocol that transfers the email. Spammers can’t fake the source of their emails.
Email sources that appear to be sending spam can be reported to a DNS-based Blackhole List (DNSBL) or “blacklist”. These services then publish a public list of email sources that they consider to be spam sources. These lists can then used by inbound mail servers to block email.
We monitor these blacklists and in the event that a TalkBox server is listed we route email traffic away from that server, investigate the incident and appeal to have the server removed from the blacklist. To date we have not had a server permanently blacklisted.
There are many things that can lead to a server being reported to a blacklisting service. These include:
- The volume of email received from a single source, particularly a rapid increase.
- Email sent to a honeypot address or domains.
- Emails being reported as spam by human recipients.
- Low engagement such as emails being deleted unopened or shortly after opening.
- Similarity with email previously identified as spam.
We can’t control all the the content that’s sent by TalkBox users however we monitor TalkBox usage and on a few occasions have stepped in when we thought the reputation of our email server was at risk.
A final note on email blacklists; while it’s easy for us to see if our servers are on blacklists we cannot see the corresponding impact on deliverability. Email filtering systems may or may not subscribe to a given blacklist.
Only send to subscribers
TalkBox allows users to upload contacts. We have no way of knowing that those contacts were gathered responsibly. They may have never given permission to be sent marketing emails, or they might have subscribed for one thing and are now being used for something else. Marketing email sent to recipients like this is the definition of spam. Not only will delivery rates be low emails that are delivered will be unlikely to be effective for marketing.
We strongly recommend only sending marketing emails to people who have explicitly given permission to be sent these emails.
This happens automatically in TalkBox. If someone receives an email from TalkBox and unsubscribes then TalkBox will not send to that email address unless the recipient resubscribes. You cannot override this.
Spam is in the eye of the beholder
The bottom line is spam is a human concept, not a technical one. If someone genuinely thinks an email is spam then it is. As an email sender your job is to not give the recipient any reason to think your email is spam.