What is the difference between POP3 and IMAP

Finally understandable: the difference between POP3 and IMAP mailboxes


  1. That's a really good explanation of IMAP and POP3 mailboxes, it really gets me ahead!

  2. Thanks, that really helped me!

  3. That's a good explanation ... until now I had only vague ideas about POP and IMAP ...

  4. a good explanation

  5. However, IMAP has disadvantages, everything is in the cloud and who “uses” everything is ultimately not visible. I also find that the provider's memory limitation is a problem. Of course, if you just write “Hello, how are you” emails, you will certainly not reach the memory limit, but if you work with a lot of attachments, you will quickly reach the limit. In Outlook I can in any case (locally, yes) access several GB of archives, I don't know how to do this via IMAP, yes, for money it is certainly also possible.

  6. Very good explanation that is understandable for everyone. Many Thanks!

  7. Unfortunately, I keep forgetting all of this, but this explanation is very helpful and still short.

  8. I like that and it's well explained.
    I use both protocols, the IMAP protocol for anytime access: smartphone and tablet. For weekly access to the laptop, the messages are picked up via Outlook with POP3 and then deleted on the server. The data is then backed up on the laptop using Outlook archiving.

  9. The explanations are good, but they don't work for me at all. I will switch to POP3 again. I have 3 email accounts with IMAP
    and whenever I delete a mail in Outlook, it is no longer on the server or on my tablet. So what do I need an IMAP account for? All e-mail accounts are free of charge and run on Outlook 2007.

  10. There seems to be some misinformation here: Every client I know (Mail, Thunderbird, Outlook) offers the option of leaving emails on the server or deleting them. If messages stay on the server, I can call them up with any other computer or smartphone. I can delete them from the computer (note: with some programs there is an option to delete mails from the server if you delete them from the computer - then of course that doesn't work), and still keep them on another computer or smartphone.
    With IMAP (where everything is stored) I would quickly reach limits, as I have to keep a lot of emails for at least a year, and once deleted they are no longer available on any device. For example, I can delete emails from my smartphone, but still have them on the computer. Therefore IMAP is not an alternative for me.

    • But that can also be argued about. The option “leave mails on server” is not an adequate IMAP substitute but at best a workaround to reduce the weaknesses of a POP mailbox. The same e-mails are simply downloaded again from another computer (according to the motto “oh fine, new e-mails on the server. I don't even know them, download them right away”). In other words, if you call up the emails on another computer, they are again rated as "new" emails - and marked as "unread" accordingly. This behavior is particularly annoying when several people access the same account. Example: A tradesman receives new emails on his mobile phone on the construction site. The same goes for his office worker (motto again: "Oh, new emails, answer right now!"). Due to the fact that the comparison is completely missing, one of them does not know from the other that an answer has already been given (or that it has not been answered).

      It also suggests that the mails are being compared (based on the motto “I can see them on different computers”). But of course they will not and at the latest with the sent mails you can see that they are only ever saved locally on this one computer. This means that all emails sent on this one device are gone if this computer ever gives up the ghost. In some cases POP3 may still work - as in your case - but in most other cases I would advise against it.

      But yes, as I said, this can also be useful in individual cases. The main thing is that everyone reaches their destination :)

  11. The alleged disadvantage of POP3 has long since ceased to exist - I synchronize z. E.g. my emails between 5 different devices completely problem-free and automatically and in real time without intermediate cloud over the Internet.
    My data is with me and only with me - and not in a "room" over which I have no control over who has access.

  12. In this respect, the example with the craftsman is, by the way, complete Qutsch and totally out of date.
    A comparison of the various mail clients and their local profiles is no longer rocket science, even with POP3. Yes, this also applies to the emails sent. These can also be automatically synchronized with all local profiles of the different computers so that the same database of emails is available on all computers.

    Regular backup of all of his systems and / or mail clients should be standard these days - so the argument of the threat of data loss with POP3 is no longer an issue here either.

  13. Hello Matthias, thank you for your comment. I don't know your technical skills, but I know from a lot of customers that “synchronizing different local profiles” already contains at least three foreign words and is anything but “rocket science”. Yes, there are now solutions for everything - assuming the technical know-how. Anyone who may be able to set up their own server also operates their own Raspberry Pi in their own four walls with all the fuss. Of course, you don't need to rent a server anywhere. As far as I know - and that's right with emails - the broad masses do not have the level of knowledge to "pimp" a Pop3 account for IMAP in this case. Regardless of the fact that this can quickly become rocket science in mixed constellations with Mac, Windows, Android and iOS clients. Maybe you can take a closer look at your exact setup, but then you can certainly draw clearer conclusions. Until then, I remain convinced that an "Ottonormalo" is happy to enjoy the convenience of an IMAP without having to manage a Pop3 including synchronization of all local folders. The underlying technology, how the mails are finally retrieved from any mail server, doesn't change anything anyway: Pop remains Pop and IMAP remains IMAP :) Best regards

  14. Hello Gino
    To synchronize my local Outlook facilities with POP3, neither special technical hardware nor a separate server is necessary - just software that synchronizes Outlook on all computers automatically in the background in real time via the Internet.
    In my case I use https://www.simplesyn.net/de-DE - and as long as I can avoid clouds, I do - I don't trust any provider.

  15. Hello Matthias and hello everyone,
    That was, in my opinion, a really constructive conversation on the subject of email sync via POP or IMAP.
    We, a small craft company, with some end devices with MS Outlook (PC office, laptop on the go, laptop home office, tablets, smartphones ...) and always the problem, on which device the mail is stored in the inbox, from which device was answered, in which saved in local folder …… and… after the computer has been renewed, the circus starts all over again.
    Often, for example, on construction sites far away from the Internet and WiFi, we need digital construction plans that are attached to an email on some device.
    Of course, I also strive to remain master of my data and prefer to use my own data storage device to access my backups if necessary and then still prefer the "aging" POP3.
    Many thanks to the reference to “Simplesyn”, we will test it extensively right away. Didn't have better input on tools of this type so far.
    For this reason I couldn't help but comment here.
    Regards Marko

  16. You explain well even I understood.

  17. Hello Gino,

    First of all, many thanks for your article. Everything is explained very well.!
    Unfortunately, I cannot agree with your statement of the advantages and disadvantages of the two systems. I am more convinced by Matthias' answer. I have to manage various mail accounts at home and I only have problems with the IMAP. Example: In addition to my own mail accounts, I have a joint account with my wife. This is synchronized via IMAP and every time one of us has read the mail on his mobile phone, it is either not dragged to the other device or appears there as "read" which is nonsense because what my wife has read , I haven't read for a long time. I actually prefer POP3 and will have to change everything now.

    Thanks and best regards

  18. The statement that IMAP mailboxes actually have no direct disadvantages is not correct. On the one hand, the emails stay with the provider, which can be seen as a cloud, so to speak. Should someone obtain access to the email access data, they can also view older emails, as they remain with the mail provider. In addition, I have no limits on POP3 mails. For example, I have e-mails that contain purchase processes, licenses, etc. stored locally for over 20 years. On the smartphone, I only get an up-to-date copy of the inbox when I'm on the go. When I am at home, the mails are moved to the local computer and remain here in my archive. Another disadvantage of IMAP is that if, for example, a mail has been deleted on the smartphone, it is no longer available on the PC. One should be aware of this.

  19. But there is a problem. The categories function (colored markings) are no longer possible in Outlook. This is possible with POP and is an important function for “lone fighters” without an Exchange server. You have to tinker again….

  20. Thank you for all the helpful information. I reinstalled Outlook 2019 and stupidly did not choose the manual setup when setting up the Gmx account. So now I have the email synchro via IMAP on it, which annoys me extremely. I want to manage my emails in Outlook and keep my GMX app tidy as it was before. I don't need any additional access to my emails there. In addition, I feel like some other users here too - I want to have sole permanent access to my emails and not know them from a provider somewhere. How can I deactivate the IMAP synchro afterwards, i.e. only retrieve or send emails via POP3?
    Is that possible or do I have to completely delete the association with Gmx and add the accounts again (and then manually)?
    Thank you in advance!