What is SMTP Server? – Definition, Deliverability and Modes

Table of Contents

What is SMTP?

SMTP is the abbreviation in English for “Simple Mail Transfer Protocol” or the same, “Protocol for simple mail transfer.

” Therefore, this network protocol will allow you to send emails over the internet from a device to a remote mail server

It is a mail server responsible for sending the message in the most efficient way possible, using the SMTP protocol.
The advantage of using it is to send mail comes from the advanced configurations.
They usually have to improve security, avoid sending SPAM, prevent sent mail from being marked as SPAM.
An SMTP server is not necessary as such to send the mail. You can send mail from your computer without going through any such server.
However, if you do not prepare effectively, you may run into multiple problems.
The first thing is that you should be allowed to send from your IP in the SPF record of your domain.
Domestic IPs do not usually have a good reputation, and the mail can mark as SPAM discarded at the destination.

Now that you understand a little better (I hope) what SMTP means, let’s get down to what interests you: the deliverability or “deliverability” of email.
The SMTP server you use to compose your emails is associated with a specific IP address.
This IP address is directly related to deliverability as it is the address that ISPs use to verify its sender’s reputation.
Due to their service’s nature, it configured by the classic email providers (Gmail, Yahoo, Outlook, etc.)do not adapt to handle sending mass emails.
This is because their IP addresses is not closely monitor, which means that you could be sending emails from the same server as a spammer.
Therefore, if you send mass emails through classic email providers like those already mentioned, you end up in the Spam folder.

To connect to the server, the software uses straightforward commands in text mode.
There are different modes of connection to SMTP servers.
The 1st connection mode use port 25 and done without authentication (without providing a login and password).
This was very convenient because it was easy to send emails.
Anyone could connect to any server without any authorization, and it was possible to send messages with any address .
This had to be remedied, but there are still SMTP servers without authentication they make spammers happy.
Some ISPs refuse messages from these open relays.
For all other more severe SMTP servers, you now need an account (login) or email address.
As well as a password to connect to the SMTP server.
For example we link to ports 25, 587 with authentication or 465 secure, with clear or encrypted password sending.
Suppose you connect to your service provider.
In that case, it is not necessarily necessary to connect to an SMTP server with a username and password because it knows you.
You connect to its network, and sometimes it only allows output to your SMTP server.
Most messaging software (heavy clients such as Outlook, Thunderbird, Incredimail, Eudora, etc.) can find servers based on your email address.
In some rare cases or unique configurations, you may need to enter the information manually.