What is POP? Or POP3? Or a POP account? And what about SMTP?

POP, POP3, and SMTP are all acronyms that you might see used when talking about configuring email. We'll look at what they mean and how they relate.


What is POP? Or POP3? Or a POP account? And what about SMTP?

POP3 and IMAP (see related articles below) are  one half of the email puzzle and SMTP is the other. POP3 is the protocol or “language” that’s used to download your email from your ISP to your mail program. SMTP is the protocol used to send mail.

But why POP? Or 3? And what are you supposed to enter when you’re asked to configure your POP3 or SMTP account in your email client?

POP is pretty simple; that’s an acronym for Post Office Protocol. A communications “protocol” is just the language used between your email program, a POP client, and your ISP’s mail – or POP – server.

The “3” is even more boring. This is version three of the POP protocol. It underwent a few revisions before it became what it is today.

To configure a POP account, you need three pieces of information:

  • The name of your ISP’s mail server that holds your email. Typically, it’s something like “mail.example.com”.
  • The name of the account that you were assigned by your ISP. This may or may not be your email name, or something like it. Or something completely unrelated.
  • The password to your account.

Email EnvelopeThat’s it. With that properly configured, you can download the email that your ISP has been collecting on your behalf.

Sending mail uses a different protocol, SMTP, which stands for Simple Mail Transfer Protocol. Again, another language used between your email program, an SMTP client, and the SMTP server to which you will send your email.

Typically, your SMTP server will be the same as your POP3 server, although that’s not always the case. If so, it doesn’t really imply that the two are related, just that the same machine is acting as a server for both protocols.

Like POP3, the SMTP server may require you to log in first, often with the same account information that the POP3 server used. (If it doesn’t require you to authenticate somehow, it’s called an “open relay” and may be a major contributor to internet spam.)

So to configure your outgoing mail, you’ll specify the name of the outgoing server and possibly the login information it will use.

And finally, note that all of this really applies only to email programs that you run on your own computer, like Outlook, Eudora, and others. Web-based email, such as Hotmail, Yahoo, and the like, simply display the email directly from their servers in your web browser – no configuration needed, other than logging in.


  1. Cheryl

    Thanks for explaining this – I just happened to view the site today and found it interesting. I had always wondered what these acronyms stood for – and now I know!

  2. Leo

    If you mean the smtp or pop3 server, that would be the name of the server handling your outgoing and incoming email respectively. That should be information provided by your ISP.

  3. carolyn

    ok so how to I get it to let me email when it says error pop3 on incoming and smtp error
    where do i change this I have comcast and also aol

  4. Leo A. Notenboom

    WHERE you change it depends on what email program you use.

    WHAT you set it to depends on your ISP. You’ll need to check with them for proper settings.

  5. Richie Ward

    I am trying to configure my mobile phone to send & receive my e-mails. For transmissions I am asked for “return address”. Can you tell me what this would be?

  6. Maniesh

    I want to configure Hotmail (free), Gmail or Yahoo id. But i am on network accessing internet with prxoy server.

    Please help

  7. sharron scott

    Thank you very much for the very valuable information about pop vs pop3 and its usage. Also keep up the good work informing people on the tech-integrities of usage on other companies products.
    Very valuable indeed!

  8. naomi McCormick

    i recently got a MacBook. i want to use my hotmail account with it. i can’t figure out what it’s asking for my:
    Exchange or

    account. For incoming mail server do i put http://www.hotmail.com?
    sooooo confusing!

    i read the info at the top but still don’t know how to proceed.

    Naomi M

  9. Joseph

    Okay, I recently got Mozilla Thunderbird, and it is asking for my POP and SMTP, I really don’t understand this. Can you please tell me how this works? Much appreciated, my email is [removed. Never post your email in the body of a comment. -Leo]


  10. Leo Notenboom

    Hash: SHA1

    This is information that your ISP would provide you. If you’re using
    GMail, start here:

    Version: GnuPG v1.4.6 (MingW32)


  11. Jamie

    I am using mozilla thunderbird and im trying to set up my hotmail account with it. But i don’t know what my POP is or what the port numbers are. how do i find those? thanks

  12. John Ball

    I use Mail demon as my mail server and tried to set up a pop account on the same computer. I put in the correct settings but it would not work. When i selected test it would complete the first three options (connect to network, send to server ect) but the last two failed (recieve from server ect). I made sure the port numbers were set at default, disabled my firewall and mail antivirus but it still wouldnt work. I set up the exact same pop account on another computer and it works fine. Any help please?

  13. Sandy

    I use Microsoft Outlook and have an account set up in SMTP. From time to time I want to send pictures or a recipe and when in this picture or recipe I select send and I enter the email of the person I want it to go to, and it goes off to send but I then get a message that it cannot send cause it needs POP3 to send. Am I able to have both SMTP and POP3 at the same time and if so, how do i set this up? Thank you, Sandy

  14. Leo

    Hash: SHA1

    Windows Explorer has nothing to do with POP3 or SMTP


    Version: GnuPG v1.4.7 (MingW32)


  15. neeraj waldon

    In Windows XP Explore where are the POP3 and SMTP settings located?It’s really very nice article giving introduction to pop3 server.
    but i want to know my smpt and my pop3 address?

    SMTP and POP3 have nothing to do with Explorer. They’re used by email programs.
  16. Sandeep

    I have a Nokia e51. I want e mails from my hotmail account to pop up and give me anotification every 15 mins. what would be the pop3 & smtp settings that i would have to put in the incoming mail server & outgoing mail server settings?
    I have tried using pop3.hot.com in both, but it dosent work.
    I have tried putting these mailbox settings in message email.

    Should I use mail for exchange?



  17. reg

    I have configured my POP3 and SMTP settings – which is the same as my POP3 server I just copied the POP3 address into the other field. I got the POP3 address from my provider. I thought it was IMAP but definitely POP3, well they told me it was POP3.
    I am now receiving email through POP3 including large attachments with pictures.
    Now I need POP-CORN. Where is the best place to get POPCORN. Do you also know how I configure my stove to receive POPCORN? Is the SMTP protocol able to forward POPCORN as well as messages received via POP3?

  18. ashish


    its been observed that my isp uses qmail server,and i want to know lil bit more abt it,
    1)does qmail supports imap?

  19. saputro

    As far as i know that SMTP protocol rely on internet connection that provided by ISP itself, then what will happen if email address was used brandA ISP and the connection used brandB ISP ??? Can the user receive / send email ???

  20. Debby

    I am trying to set up my Mail account on my Mac. It asks for my email address and password which I’ve filled in. Then the incoming mail server details, i.e. POP, IMAP or Exchange. Then the name of the Incoming Mail server. I don’t know what this is or how I find it. My ISP is Firefox and my normal email account is with MSN [email address removed]

  21. renae

    I’m really not computer savvy, and I get tired of trying to send certain e-mails which require this info., which I don’t know. I use yahoo e-mail, what should I put when it asks about http, pop3, whatever….?????

  22. Charlie Scultz

    #1: The host ‘smtp’ could not be found. Please verify that you have entered the server name correctly.
    Subject ‘Emailing (Email), Account: ‘pop3’, Server: ‘smtp’, Protocol: SMTP, Port: 25, Secure(SSL): No, Socket Error: 11001, Error Number: 0x800CCC0D

    The host ‘pop3’ could not be found. Please verify that you have entered the server name correctly.
    Account: ‘pop3’, Server: ‘pop3’, Protocol: POP3, Port: 110, Secure(SSL): No, Socket Error: 11001, Error Number: 0x800CCC0D

    I have Vista. I can get mail, just not send.
    That was why I had trouble mailing back to you. I had to restart several times.

  23. Paul Kleeween

    Had to rebuild my Windows Xp computer.
    Input the wrong pop3 and smtp addresses.
    How do I get to the place where I can correct these entries? It just won’t connect to the internet.

    Depends entirely on what email program you use.

    – Leo
  24. Riley

    I’m trying to add another account to my Windows Live Messenger and I have everything else but it’s telling me that I need to put in my “POP server”. I don’t even know what that is! How would I find that?

    If it’s asking for a POP server, then you’re not configuring Windows Live Messenger. POP is an email thing, and it sounds like you’re somewhere in Windows Live Hotmail instead.

    – Leo
  25. bb

    ? re my level of competence: I don’t even know what’s meant by using HTML tags for style ;-)and you expect me to really comprehend all the logic and intricacies of pop3, SMTP, IMAP, whatever?;-)) It was six years before I realized I could move ‘Windows’. I’ve used ONLY Yahoo’s web based email program, and whatever I have not deleted I can access on-line. I’d like to insure permenant accessibility to that material and hope I could handle simple directions, if there are any, as opposed to theoretical or technical explanations, to achieve this goal. That there were recent comments was encouraging, even though I’m even dizzier now that I’ve read them ;-)). Would downloading an ‘application’ such as Thunderbird, et al, be the route to go? Is transferring or sharing this material possible somewhere else on line, in the event Yahoo ‘goes down’ for example?. I use two different ISPs and have a few web-based email accounts and run XPsp2, if any of this makes a difference. I am in a panic which may account for why much of the discussion isn’t sticking to the brain. I sure hope you are for real.

  26. Lesely peake

    I,m trying to use windows mail for my emails I’m with optusnet
    windows asks whos my incoming mail pop3server
    and whats my outgoing email smtp name
    no idea!
    must have it half right as it’s picking up my in mail but I can’t send

    You’ll have to ask your email provider for the correct setting.

    – Leo
  27. Baverly

    I was trying to scan an news article to e-mail to a friend, scanned ok, put in the e-mail address and I recieved an ERR message.
    Same as #1 that Rene on 11/11/2008 recieved about the POP# etc….What does that mean??What do I need to do. I have windows XP??

  28. Seveline Estrella

    Good day! I’ve read the article and I’m still confused. The scenario is this: I am using Yahoo! Mail for sending/receiving e-mails but I would like to use Mozilla Thunderbird instead.How will I connect my Yahoo! Mail account with my Mozilla Thunderbird account? how will I know what’s my POP and SMTP? Hope you could help me?

    In the U.S. I don’t believe Yahoo makes a POP3/SMTP interface available – it’s web only.

    – Leo
  29. Seveline Estrella

    By the way, I’m using Windows Vista as my computer’s OS.

    I’ll be glad if you could help me with that.

  30. Clay Robson

    Somehow I have enabled POP email on my computer. It doesn’y work & I don’t want it. Every outgoing MSN email is not sent unless I change my “from” address to a MSN designation on the dropdown. If I forget to do that, the message is not sent. How do I terminate it?

  31. Kari Reynolds

    I have a yahoo account and I am trying to use Entourage on a Mac to send and receive my emails.
    I keep getting the -3260 error. Connection error has occurred. Do you have any advice ?

  32. francois

    I am getting that port 110 error how do I fix it on this computer. I have set up my emails on another computer and everything is working alright and then when I go to my own computer it is giving me this error report:The host ‘mail.clients-login.com’ could not be found. Please verify that you have entered the server name correctly. Account: ‘mail.clients-login.com’, Server: ‘mail.clients-login.com’, Protocol: POP3, Port: 110, Secure(SSL): No, Socket Error: 11004, Error Number: 0x800CCC0D. PLEASE HELP URGENTLY

  33. Meng

    Hi, never had this problem before, but failed to send an email from Outlook Express with the message:
    The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was ‘[email removed]@yahoo.com’. Subject ‘Members Only May 1-3 Weekend Sale’, Account: ‘mail.qtiq.com’, Server: ‘mail.qtiq.com’, Protocol: SMTP, Server Response: ‘501 Bad address syntax’, Port: 25, Secure(SSL): No, Server Error: 501, Error Number: 0x800CCC79
    Please help!

  34. Myron

    Whenever I attempt to send-out an e-mail, a message appears asking me about if I use POP, POP3 or HTML. I don’t know which I have so my messages never get sent. What must I do?

  35. Sheree Murphy

    Everytime I try to send mail in Outlook Express it always says error: either the server name or email address is not correct or server not found make sure you are using the correct server name etc. Help? I don’t know what to do for this problem.

    Not to sound to snotty, but consider following the advice in the error message you were given: confirm that your SMTP settings are correct. Check with your ISP or Email provider for what they should be.


  36. Gail

    Having trouble understanding e-mail set-up–nothing’s getting sent: Recently changed service provider from Comcast to Verizon. My name is Gail. My e-mail name is t….@verizon.net. How do I enter terms in my Outlook Excpress program? Thank you

  37. Agostinho


  38. Kim Marchant

    i want to set up an email account for my phone. i don’t know what to put for the (outgoing server)SMTP server/POP3 (or here it’s asking for IMAP4)…what do i put. i have a hotmail.com account on the net…can someone please help?

  39. CISO

    Just a quick tip for all the mail servers (SMTP) admins out there reading this page : if you want to reduce the number of spam messages going thru your mail server, use this inexpensive tool (a free version available also) and protect your mail server now! dont wait for the spammers to find you:

  40. George

    The above address is my personal hotmail email account (provided by msn through Verizon). I want to start receiving email for my new business in the same account, but with a business name email address, ie XYZ@hotmail.com. I have been trying to set the email account up but can’t seem to get it done. Any help would be greatly appreciated. Thanks. George

  41. Shiela

    I am trying to set up my email from work on my phone. I was able to set it up, but the problem is I can’t send or reply on emails it always saying my account is set up wrong. Can you help me set it up?

  42. Paul Kinney

    I recently purchased a new Windows 7 (64-bit) based laptop. I installed my {email removed} POP3/STMP email as a Windows Live account. I can send an email to myself and receive it. I can also send emails to others. Sometimes I receive emails from others but most of the emails that other people tell me thay have sent do not ever reach me. And the persons who send these missing emails do not receive any notification that the emails were rejected. I also have a web-based hotmail account and this works perfectly. Is there any diagnostic log I can set up to detect what the problem is? Please help!

  43. Larry

    I have tried sending pictures out folder or files but each time I try sending them out POP3 or SMTP which prevents me from sending out my pictures so what do I need to do fix this problem?

    It depends on what “prevents me from sending” means – we’d need to see error messages and understand exactly what email program you use and what steps you use to include images.


  44. valeria

    Good day,

    I need your help. I have been trying to set my windows Live mail for Windows 7 32 bit. But no result – I cannot open my inbox for these 2 accounts! On Windows Vista they worked properly.
    Then I downloaded missing dll drivers and Microsoft Silverlight 5 beta – no result.
    Then I tried to set these addresses in Mozilla Thunderbird – but even no connection with server.

    Tell me please, what is the problem? What should i do?
    I tried very hard but still cannot read my mails, it upsets me((( I have lots of necessary mails connected with my job(

    If there will be no good way out – can I transfer my mails to other (not hotmail) accounts?

    Waiting for your reply. Will be gratefully thankful.

    Well, for one thing if this is a hotmail account you can simply to go http://hotmail.com, login and access your email. To use Hotmail with a program like Thunderbird you need to use the POP3 settings as outlined here: What are Windows Live Hotmail’s POP3 and SMTP settings? Be very careful to get the correct.


  45. Gursaran Singh Jaswal

    I have downloaded an auto responder and it demands POP name . What name should I fill up For Yahho india ?

    I have no idea. You’ll need to contact Yahoo India customer support.


  46. Nicole

    Ok well I don’t have a computer,I have an iPod that I can get on email,but today I went to go to my email and it wouldn’t let,it said go to mail settings.how do I go to mail settings on my iPod?

  47. marjorie

    Hi Im not very up on computers and my email will not send , Ive tried all the different sites but to be honest I dont understand a word of it please help.

    Well, I’m afraid that’s not nearly enough to go on. Please ask your question here: http://ask-leo.com/ask, and be sure to include all the information that page lists, most importantly the email system or program you’re trying to use, and any and all error messages.


  48. Glenn P.

    Some ISP’s are more particular, and may insist upon access via specific port numbers, and/or via SSL, as well as proper username and password, for E-Mail account access.

    It scarcely needs saying that these ISP’s are pains in the gazobo!!!     :(

    The process may be painful, but there’s a very important reason ISPs do this: spam. By requiring authentication and using non-standard ports they can deal with spam much more agressively. By connecting correctly it’s extremely unlikely that your email will be blocked by that ISP as spam as you send it out.

  49. Leo Marquez

    It is refreshing to hear someone who answers the questions that a person who asks about computers in a clear and consice manner. I have taken classes in MS office, Word, Excel and I, and many other people, must operate a computer for their jobs. We don’t want to write programs or be an IT person. The computer replaced the pen and pad or the typewriter it is a tool to turn out work product. While it is true the more that you know about them the more effcient you are but I am not enthralled with a computer. After all the classes occasionally I have questions questions that don’t force me to understand how to program the thing. Thanks Leo (suprise, that’s my name too.

  50. marina

    well my hotmail was encrypted what shall i do to get back my email pls

    I don’t know what you mean by your Hotmail being “encrypted”. Hotmail does not encrypt.

  51. Mark Jacobs

    Your ISP is the company that you get your internet access from such as AT&T, Comcast, Verizon etc.
    This article on Ask Leo! – should clear up the confusion of Microsoft’s different Live brands. What is windows live?

  52. Sally

    I can’t open my email at excite.com and am trying to have it sent to my gmail account. I don’t seem to be having a lot of luck. Any suggestions?

  53. Robert A.

    I’ve been using Thunderbird email for several years with my local ISP. I now have Thunderbird opening all my email without any command from me. how can that happen and how can this be remedied?

    Thank You!

  54. Mark J

    To turn this feature off, click on “Tools” then “Account settings”. Select “Server settings” for the account you want to change and deselect the checkboxes for “Check for messages at startup” and “Check for messages every xxx minutes”

  55. vipin kumar chaudhary

    In computing, the Post Office Protocol (POP) is an application-layer Internet standard protocol used by local e-mail clients to retrieve e-mail from a remote server over a TCP/IP connection.

  56. Judy Ashby

    What do I do with the little box that keeps popping up titled “pop2” with my email and directing me to enter a password in place of the asterisks? No matter what I enter or how many times I delete the box, it comes back. Is something bad going to happen to my computer?

    • Are you sure that’s a “2”? POP3 is what we expect. Typically that message happens when your email program is trying to download email from an account, and the account server is saying that you have the wrong account name or password configured. The box should include more information about exactly what email account it’s complaining about.

  57. Ann

    I just wanted to say thank you Leo, for helping us as a community to understand the how’s, what’s, whens and whys of the workings of the computer and the many components that it’s comprised of. Again thanks for being that someone.

  58. Michelle

    I just bought a Verizon 6 plus, 64 GB! I want to use many of the apps that this phone offers! So, unfortunately this will not be the last time I have a question. I want to do everything correctly! First question is, What password, “that is required” do I enter for POP Account do I enter to begin for neo.rr.com? My home computer is a Dell 8 version ! Sometimes I use Internet Explorer, but I also have a Chrome account set up also!?

    • That would be the password you use to login to your neo.rr.com account – I’m not sure how else to put it. You should be required to enter a password when you check your email normally – so this would be that password.

  59. GerryR


    I have read at least a dozen articles about, “The Advantages of IMAP”. This article was far and away the very best one I have ever read. If there was a Hall of Fame for computer articles, this would deserve to be in it. Thanks for this wonderful explanation!

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