What are POP3, IMAP, and SMTP?
Hi, everyone. Leo Notenboom here for
Askleo.com. If you're not subscribed to my free weekly
confident computing newsletter, visit
Com newsletter and sign up today.
Tips, tricks, and definitions like this every week in your inbox.
So the world is full of confusing acronyms
and especially the world of technology and computers.
These POP, 3, SMTP, IMAP,
these are really old acronyms, and you've probably encountered them as
you've been playing with email, as you've been configuring email.
But what do they mean?
What are they and why do they matter?
Well, let's take a look. POP.
POP stands for Post Office Protocol.
POP3 simply means it's the third version of the POP protocol.
And in fact, POP 1 and POP 2 didn't last for very long.
And to the best of my knowledge, there's no rumblings even about a pop 4.
So POP3 and POP are pretty synonymous.
It is the language that an email program running on your computer uses to
communicate with your email server to download your email.
So for example,
if you're running a program like, say, Thunderbird,
and you have it configured to use POP3, then it is POP3, the language of POP3
that is used between Thunderbird and your email server to literally download your
email and remove it from your online service.
Your email then lives on your PC in your copy of Thunderbird.
I use Thunderbird as an example.
POP3 has been around for so long,
almost every desktop email program and a bunch of mobile email programs can
all handle connecting to email services using POP3.
Imap.
Same, only different.
Imap stands for the Internet message access protocol.
It's like POP3 in that it is a language that is used between an email program
running on your device to access your email on your email services servers.
The difference is that IMAP makes
a fundamentally different assumption about where the email lives.
With POP3, you're downloading it so
that your master copy of your email is on your PC.
It's just that one copy.
Well, that makes it difficult to access
your email from multiple different devices because it's only on your PC.
Imap makes the different decision.
Imap assumes that the email server,
the service you're using holds the master copy of your email.
And then using IMAP, all you're really doing is you're given
a window onto that master copy from any number of different devices
so that you can then read your email, mark your email as read,
delete your email, do all of the things with your email,
and have it appear on all of those other devices because it's all happening
on the master copy on your email services server.
It's really common these days.
And in fact, it's generally what I
recommend only because you generally will have more than one device these days.
If you've got a phone,
if you've got multiple computers, if you've got any number of different
things that can access your email, using IMAP so that they are
all natively in sync with one another is a great solution.
Okay, what about SMTP?
Simple mail transfer protocol.
You know it as the way that an email program on your desktop or on your device
actually sends the mail you're sending to your email service.
So when you configure your email account settings, one of them is the SMTP server.
POP3 and IMAP, they're used for receiving email.
Smtp is what you're using to send email.
Here's the unknown or not very well known
secret of SMTP is that it's the workhorse of email.
It really is, because not only is it used to send email from your PC to your email
server, it's the protocol that's used to send
that email from server to server, from server to server to server to server,
however many hops it might take to finally get the email to its destination.
So SMTP is happening all the time across all of the email services.
It's sending email.
Simple mail transfer protocol doing a lot of transferring.
Now, I do want to point out that web mail works differently, mostly.
I say that because when you access
email using a web mail interface like Gmail's web mail interface or Outlook.
Com or so forth, you don't know what's going on behind the scenes.
You are accessing the master copy of your
email on their services, but it's up to them how they access it,
what's appropriate, how they got it implemented.
They could be using IMAP, absolutely.
Generally, they don't, but they could.
But the bottom line is it's different.
The one place where they overlap is that some email services
will allow you to fetch email from another account into your account using POP3.
In a sense, that makes your online account for, say, Gmail,
like a desktop email program in the sense that it's now reaching out to some other
account somewhere else and downloading email.
But that's really the limit of the overlap.
I hope this helps you understand a little bit of how email is processed and what
these acronyms actually mean when you are faced with having to at least fill
in the form than when you're configuring an email program.
For updates, for comments,
for links related to this topic, and more, visit
Askleo.com/2143.
I'm Leo Notenboom.
This is Askleo.com.
Thanks for watching.