Deliverability is about getting a very high percentage of the emails you send delivered to the server and into the inbox of your recipients. Unfortunately too many people fail and end up with their emails being rejected or dumped in spam folders.
To do that you need to pass various technical and reputational checks. Here is a checklist of some of the key points to watch out for to meet current sender authentication and other technical requirements, keep your reputation clean and achieve those high delivery rates!
Purchased Lists
If you are wanting to send to a purchased mailing list - you need to think very carefully. Many may not be opt-in or are using addresses scraped from web sites.
Getting it wrong could cause reputational damage risking delivery of all your emails.
Adding Recipients
You should only email people who have specifically opted-in direct with you and are expecting to receive email from you. When adding people to your list it should be using a confirmed opt-in - so you send them only one email to check they want to be added to your list and they have to click a web link to confirm.
List Quality
Be careful emailing recipients you have not contacted in a long time. Ideally keep in frequent contact with your recipients as if they have not heard from you in 6-12+ months they may forget they signed up. It is also a good idea to segment your lists and keep a record of how and when they signed up.
Bounces
If you email a recipient and get a failure message (bounce) - look at the failure and decide if they are hard / permanent failures they should be removed. If an email address is no longer valid you are paying to deliver to addresses that will not be delivered and some recipient systems may negatively score your attempts to send to invalid addresses. You should aim for a bounce ratio of 0-2% maximum.
SPAM Complaints
If you do get a spam complaint you should not send any further to that recipient. If you believe it is in error we would recommend you contact the recipient by alternate means to clarify. Not removing addresses that complain will just result in further complaints and possible blocking / blacklisting. You should aim for less than 0.1% complaint ratio.
ESP
Rather than sending from a server on your own Internet connection consider using an Email Service Provider. Typically they will make complying with various DNS / IP / Sending Authentication requirements simpler and will often also process bounce data and other important metrics for your account.
rDNS/PTR/HELO
You must ensure the DNS and server HELO records for the IP you are sending from are valid / correct.
SSL/TLS
The server you are sending from must support modern TLS protocols when sending - some recipient systems will not allow or negatively score email from non-compliant servers.
SPF
Sender Policy Framework specifies the IPs, hosts, services that are permitted to send from your domain name. Your domain must have a correct SPF record.
DKIM
Domain Keys Identified Mail is a method of cryptographically signing the messages you send to ensure they are authorised for your domain.
DMARC
Domain-based Message Authentication, Reporting and Conformance is an email policy record. It builds upon SPF and DKIM and adds reporting to further improve the security of legitimate emails.
Dedicated IP
Sending your emails from a dedicated, static IP address is preferable and typically recommended when you are sending at least 25-50k messages per month. A dedicated IP allows you to build a positive reputation not affected by other users on a shared IP address.
Feedback Data
Sign up for services like Microsoft SNDS and Google Postmaster to help track domain / IP reputation. Some ESPs may provide Microsoft SNDS data automatically (subject to you sending at least the minimum level of emails to generate the reports - typically 100+ emails per day for Microsoft).
Send Consistently
Email destinations typically prefer to see consistent email volumes rather than all your email sending in one or a few days per month as large peaks can look like a system / IP address has been compromised.
Monitor
Sign up for accounts with major email destinations like Microsoft and Google so you can test and ensure your emails are reaching the inbox and help diagnose any issues should they arise.
Content
Avoid spammy content in subject lines, text in ALL CAPS or lots of !!!. Do not send emails that are just a single image of the content as there is no content for recipient spam filters to work on.
Personalise
Rather than sending the same email to every recipient on your mailing list - personalise the content where possible. Showing content more relevant to the recipient is likely to increase engagement and reduce the risk of spam filters seeing the same content as potential SPAM.
Unsubscribe
Include a working and easy to use unsubscribe option in your email body text and a List-Unsubscribe header in the email.
Safe Sender
To ensure your recipients recognise the emails - send from the same domain they signed up with.
Encourage your users to add your email address to their address book or 'safe sender' list.
Out of Control
Remember your recipients and their ISPs are free to set their own policies. Some systems will go so far and suspect any email not specifically flagged by the recipient as safe as spam so despite having everything configured perfectly you may face some issues.
Following these will certainly help minimise delivery problems!
Contact
If you have any suggestions or questions Contact Us.