Understanding email deliverability

To better understand message deliverability, it’s crucial to know who is involved and what the email campaign journey looks like. Learn what stages the message must go through to ultimately reach the recipient. 


  1. Who’s involved in email deliverability
  2. The journey of an email campaign 

1. Who’s involved in email deliverability

There are four parties involved in the email deliverability process – the senders, the ESPs, the ISPs, and the recipient. 

  • Sender

The sender is the company or the individual that schedules the email message.

Depending on the fact if the original sender has its own email infrastructure or not, the email message can contain different sender data:

    • envelope “from” – this address is displayed in the recipients’ inbox, 
    • “from” address – indicates the infrastructure responsible for sending out the message.
  • ESP

Email Service Provider is a company that offers bulk email sending services. Besides the infrastructure which is used for physical campaign send-out, they offer also functionalities that help design, personalize and analyze the email campaign. 

An important element of an ESP offering from a deliverability perspective is a warmed-up IP address with a good shipping reputation.

SALESmanago is a good example of an ESP. 

  • ISP

An Inbox Service Provider is a company that offers mailbox services. Every ISP, whether large or small, has its own anti-spam system and blacklist report that lists suspicious addresses, or senders who use bad practices.

Companies may have their own email infrastructure and don’t use external ISP. In such a case, they use their own policies to filter incoming emails.

  • Recipient

The person who has opted-in to receive the email. Usually, the individuals have to sign up to receive messages from various companies.  

Recipients can use a private, individual inbox or a business one, as well as apply individual filters, install adblock systems, or choose to unsubscribe to customize their inbox.

2. The journey of an email campaign 

In order to refine the subject of email deliverability, it is crucial to analyze policies and best practices in detail at every stage – from building the mailing list to creating and delivering emails, to their final evaluation. 

The following steps must be taken for the campaign to reach its audience:

If you need more information about the topic mentioned above, please contact us: support@salesmanago.com +1 800 960 0640