When you think of email deliverability, email delivered to the inbox should come to mind.
In an ideal world; as the email sender, your message is not blocked by spam filters, blacklists, appliances, new protocols, the receiving ISP, or by the recipient’s email client’s configuration. The mail is simply delivered to the inbox, it’s read, the call-to-action processed, and the user forwards the email to a friend.
But that’s in an ideal world. In the real world, even though there is much value in email as a source of communication, there are aspects of email that some consider intrusive, namely SPAM. Therefore, before the email is considered deliverable to the inbox, it is scrutinized, authenticated, and examined, along with its sender and their reputation.
Email delivery issues can be caused by the sender, the email message, or both. 
As a sender you should be cognizant of your sending reputation or sender score, as your overall email sender reputation follows you. It is evaluated by receiving ISP’s who use it along with other measures to decide to deliver your email or not.
Your sender reputation is a compilation of the IP address(es) and domain(s) you are sending from. IP addresses normally identify the location the sender originates from (but not always). In addition, unless you have a dedicated IP address, most likely you are sharing an IP address with other email senders.
Sending email campaigns on a shared IP can tarnish your reputation if someone on that address does something to get it blacklisted. It may be best to invest in a private IP address, one to use just for your email sends.
However, a private IP doesn’t mean you can load up your email list and start sending: A brand new sending IP address also sends a message to ISP’s that you’re a new sender without a reputation. Consequently, it is advised that you take time to warm up that IP address before you go whole hog on it.
The process of warming up an IP address helps establish your legitimacy among ISPs as a reputable email sender.
Sending on a good IP address is not enough to be a successful sender you need to show that you have control over the domain you’re sending from. This is done with DMARC.
Along with DMARC is the use of DKIM, SPF and BIMI. When these authentication protocols are set up properly, the email receiver servers will consider you as a legitimate sender.
But wait there’s more: The Email Message
The message should be relevant, personalized, and follow best practices.
- Use confirmed opted-in with new subscribers Keep your list clean by removing inactive recipients from your list. Create a sub list for a re engagement campaign of recipients who have not opened or clicked your emails in a few months.
- Avoid buying or renting email addresses to inflate your subscriber base.
- Be consistent when you mail, weekly, biweekly, and monthly. Don’t mix it up.
- Strive to use the same FROM address for all your email campaigns.
- Take care of complaints.
- Keep your list clean, remove unsubscribes for example.
- Monitor blacklists and if you land on one, follow the recommendation (usually available within the ESP delivery report) to remove your IP address from the blacklist or call your ESP for assistance.
- Optimize your emails for all connected devices, honor unsubscribes, segment your email for better engagement, and test before you send.
Because this is the real world and not the ideal world, it is getting harder for senders to get those messages in the inbox. In the real world, some of your emails may not make it to the recipient, being unfairly blocked for any number of reasons. Strive for a good sender reputation and follow best email practices for best results.
Find out what you know on this subject- we invite you to take our quiz just for fun https://mailinglistservices.com/quiz/email-marketing-quiz/