SMTP VS IMAP – The Difference (+Table Of Comparison)

SMTP VS IMAP – The Difference (+Table Of Comparison)

Emails are the lifeline of sales, and you must have read enough about using this channel of outreach effectively. Email marketing boasts of an ROI of a whopping 4200% which means that you earn $42 for every $1 you spend. The numbers successfully explain the popularity of the email outreach channel. However, have you ever thought about how you send and receive emails? It is made possible with the help of the 3 protocols – SMTP, IMAP and POP3. Wondering why we are discussing this on our blog? It is because we use a lot of things in our everyday tasks yet fail to understand how they work. Learning how email works will be helpful to you as a salesperson. Know what are these email protocols and get ready for SMTP vs IMAP.

Table Of Contents

What Is SMTP?

SMTP is the short form for Simple Mail Transfer Protocol. It is an industry-standard protocol developed back in the 1980s and is used to send emails from an email client to an email server. Here an email client refers to Gmail, Microsoft Outlook, Apple Mail and the like.

SMTP also enables the relaying or forwarding of emails from one server to another, which is important when the sender and recipient don’t use the same email service provider. 

The port numbers used for SMTP are 25, 465 and 587 for a TSL encrypted connection. Read the difference between SMTP VS POP3

What Is IMAP?

IMAP stands for Internet Message Access Protocol that manages and retrieves email messages from the receiving server. In short, the protocol’s role is to receive messages. 

It is the most commonly used protocol used to receive emails. It is the brainchild of Mark Crispin that has witnessed a lot of upgrades since its inception in 1986. At present, IMAP4 is used everywhere, which was previously named IMAP2bis. 

IMAP stores the email message on the server and syncs it across several devices. It also has message flags to mark a message as read, deleted, or replied to. 

The port number used for IMAP is 143 and 993 for secure SSL and TLS connection. Read the difference between IMAP VS POP3

SMTP & IMAP In Action

As already mentioned, you use both SMTP and IMAP in your daily life when you send an email or receive it. Here’s how they work,

1. Once you are done writing your email and hitting the send button, your email client sends your email message to an email server using SMTP.

2. The email server uses SMTP again to send the message to the receiving email server of the recipient.

3. As soon as the SMTP transmission gets received, the recipient’s email client fetches the email message with the help of IMAP and places it in the recipient’s inbox. 

Difference Between SMTP vs IMAP

SMTP VS IMAP-Infographic

The primary difference between SMTP vs IMAP is that the latter is a protocol for sending emails, while IMAP is a protocol to manage and retrieve email messages from the server. 

Where the protocols are used is also different. IMAP is used between the email server that stores the emails, and the client retrieves the email. On the other hand, it is not just the email client that uses SMTP to send emails to the email server. Email servers use it to send an email message to another server too. 

SMTP vs IMAP – Quick Comparison

Short form forSimple Mail Transfer ProtocolInternet Message Access Protocol.
What does it do?It sends email from an email client to an email server and between two serversIt manages and retrieves email messages from an email server
PortsPorts used are 25, 465 and 587Ports used are 143 and 993

Why Is It Important To Know How Email Works?

Knowing how email works is important as it is the most common communication channel in the business world, and it is not going anywhere in the upcoming years. So, in general, knowing it’s working would serve as some added knowledge about a task you do almost every day. 

Email Marketing Tools VS Sales Outreach Automation Tools In SMTP Terms

If you reach out to prospects using email, there is a high chance that you use a sales automation tool because handling all of it manually can be a tedious task. For sending marketing emails and newsletters, you may be using a marketing automation tool like MailChimp. For sending cold emails, you may be using a sales outreach automation tool like SalesBlink. 

There is a difference between tools meant for email marketing and sales outreach automation concerning SMTP. 

Here’s how an email marketing tool sends emails,

Your email marketing tool hosts SMTP servers of their own which means your emails don’t go from your usual server. While your address will appear as the email sender, the email will not go from your mailbox. Also, the emails will get sent quickly as the tools use a lot of SMTP servers. It is also worth noting that the marketing emails hit recipients’ promotions and updates folders. 

Are you wondering why you can’t send cold emails using an email marketing tool? There are enough reasons for not doing so. 

Reason 1

Email marketing tools are not meant for sending cold emails. It is not even there in their policy/terms of use.

Reason 2

Using email marketing tools will land your cold emails in the promotions or updates folder, thereby minimizing the chances of the email getting opened or replied to. Learn more about the difference between cold email and email marketing

So, as you can see, it is not useful to use an email marketing tool to send cold emails. 

Let’s see how sales email automation sends emails.

The process of sending emails is different for sales outreach automation tools. For instance, SalesBlink uses the SMTP on your email server to send emails to prospects. So the emails are going from your mailbox, which is why you cannot send thousands of emails in one go.

The emails get sent one by one, and it can take a lot of time, even if your email campaign has only 40 prospects in it. However, the outcome is that the messages hit the primary tab of the recipient’s inbox so that the message is more likely to be opened. Also, as soon as there is a reply from the prospect, SalesBlink identifies it and stops the whole follow-up sequence so that the messages scheduled don’t reach them.

As you can see, it is better to use a sales automation tool to send cold emails.


SMTP and IMAP are two protocols that you need to send and receive emails, respectively.  Understanding both of these protocols is helpful when you want to set up sender email accounts on sales outreach automation tools like SalesBlink. After all, a little working knowledge would not hurt anyone. 

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