In your previous tips you describe the process about switching from POP3 to IMAP and from IMAP to POP3.
By the way, now that any modern mail client (including the webbased ones) supports a Sent folder, you typicaly have to use both SMTP and IMAP to send a single mail. And there's a race condition between sending the e-mail over SMTP and successfully saving the e-mail to the IMAP Sent folder. Using IMAP for sending e-mail is a way to avoid this race condition.
I’ve always used POP3 in the past without giving it much thought as it worked for me. I recently found out that my provider actually supports both methods. So I can choose but that also brings my question;
Which one should I choose?
Simply stating which one you should choose isn’t that easy as it depends on various factor but also your personal preference.
In addition, there are various technical differences and limitations to consider which could also influence your decision.
In short…
Before making things complicated, there is actually a pretty good rule of thumb to go by to quickly make a good decision which fits most common scenarios:
- If you mainly work with your email from 1 computer and online mailbox space is limited, POP3 is the way to go.
- If you frequently use multiple devices to work with your email and/or online mailbox space isn’t directly limiting you, IMAP might be the better choice.
Of course, this is just a guideline and there often good reasons to do otherwise or even access your mailbox with POP3 from one computer and via IMAP on another computer or mobile device (see the “My configuration” section for one such example).
POP3
When you configure your mail account as a POP3 account in Outlook, everything that is in your Inbox folder of your webmail account will be downloaded. It really only supports the Inbox folder, so when you’ve stored your mail into various folders in your webmail account or have items in your Sent Items folder on the web, these won’t be downloaded (but still can be).
POP3 is download only, so changes you make locally, will not be uploaded back to the server nor to any other computer or device. This also includes Sent Items and the Read/Unread status of your messages. If the message was already marked as read on the server, it will be downloaded as Unread in Outlook.
Originally, POP3 accounts directly removed the message from the server when they’ve been collected in Outlook. Starting with Outlook 2010 and continued in Outlook 2013, the default setting is to leave the messages on the server for 14 days after they have been downloaded in Outlook. You can alter this setting in any version of Outlook.
Another major characteristic of POP3 accounts is that, when you have multiple POP3 accounts configured in Outlook, you can set them to download to separate mailboxes (pst-files) in Outlook, to separate folders within a single mailbox or simply deliver everything to the same Inbox folder.
Note that data of POP3 accounts only exists on your local computer. Make sure that you include the pst-file(s) that you have are included in your backups.
IMAP
When you configure your account as an IMAP account in Outlook, everything that is stored in your webmail account will be cached. I say cached, because with an IMAP account, there is an active sync taking place between your data in Outlook and your webmail account. This means that all your folders that exist on webmail now also exist in Outlook.
This sync relation means that any changes that you make in Outlook, will also be uploaded back to the server and thus other computer and devices that you have configured with this IMAP account. This includes your Sent Items, deletions and the Read/Unread status of your messages.
A thing you’ve probably directly noticed is that you now have an extra folder set in Outlook or have some folders marked with “This computer Only” (since Outlook 2013). This is because IMAP only supports synching Mail folders and doesn’t offer support for other folder types such as Calendars and Contacts. For more information about this see:Remove empty Personal Folders list and Don’t risk losing your Contacts and Calendar when using IMAP in Outlook 2013.
Other notable differences, compared to POP3, is that the use of Flags with Reminders and Categories is limited. And you may have to manually configure some folders to keep your Sent Items and Deleted Items folder synched as well (which is even a bit trickier in Outlook 2013).
In addition, deleting items works a bit different as well in IMAP accounts as IMAP doesn’t really have the concept of a Deleted Items folder. Instead of moving items to a Deleted Items folder, messages get “marked for deletion” and need to get “purged”. You’ll recognize these items with a strikethrough. Outlook 2010 and Outlook 2013 purge deleted items automatically upon switching folder and create a copy of the item in the Deleted Items folder.
Note that synching isn’t the same as having a backup. When a message gets deleted on any device, it will also get deleted on the server and any other device as soon as they sync. Backups can be made on the IMAP server or locally via exports. Don’t forget the Calendar, Contacts, Tasks, Notes and Journal folders or the pst-file containing them.
Limitations of both IMAP and POP3
Of course, the biggest limitation is that you can’t sync Calendar and Contacts folders with neither POP3 nor IMAP. If you also want support for this, you’ll need a 3rd party syncing tool such as CodeTwo Outlook Sync or iCloud or (even better) use a mail account type which also support synching these folder types such as an Outlook.com account or an Office 365 (Exchange Online) account.
An Outlook.com account can also be used with your own current email address, even when you don’t have a domain of your own.
My configuration
Before I switched to Office 365 (Exchange Online), I’ve used the following configuration:
- Main computer
POP3 with the option to leave messages on the server for 31 days. - Laptop, tablet and smartphone
IMAP and every month (or when needed) I downloaded the Sent Items of the IMAP account on my main computer.
For me, this worked because I mostly worked on the “main computer” where I wanted to have my full mail archive. When I was “on the road” or simply working on another device, I usually only wanted to keep up with new emails, so only having the last 31 days available wasn’t a big limitation.
This configuration also gave me the benefit of having the Calendar and Contacts folder within the same pst-file and some other features which don’t really play nice with an IMAP account like Categories and Flagging messages for Follow Up as already mentioned in the IMAP section.
![Devices? Devices?](/uploads/1/2/5/8/125841372/388508162.png)
Changing Email Protocols:
There might come a time when you’ve setup your mail client to check email on the server via POP3 or IMAP and you decide you want to switch to the other protocol. Unfortunately you can’t simply flip a switch to do this, but you can re-create your email account in your mail client to use the protocol of your choice.
Difference between POP3 vs IMAP
When you need to check your email on the server, there are 2 different protocols POP3 or IMAP available to use. Depending on how you utilize your email, one way might be more preferable to the other for you.
With POP3 (Post Office Protocol) this would be the same as simply going into the post office, removing everything in your post office box and taking it home with you. You retain the physical copies of all of your mail that has been sent to you, and the post office (server) doesn’t have to deal with them further.
With IMAP (Internet Mail Access Protocol) instead of simply taking everything out of your box and home with you every time. You instead grab a copy of each message, and the original stays in the post office box (server). This is convenient if you have multiple devices such as a desktop, laptop, smartphone, and tablet all trying to check mail from the same account.
Switch from IMAP to POP3
Switching an IMAP account to POP3 would allow you to alleviate the server from managing your emails, and instead they would be stored locally on your computer. You would just need to create a new POP3 account in your mail client, then drag any messages off the server from the IMAP account you wish to download.
If you’re having IMAP resource usage problems switching an IMAP account to POP3 is a great solution!
![Automatically Sending Emails Using Several Individual Imap Accounts Automatically Sending Emails Using Several Individual Imap Accounts](/uploads/1/2/5/8/125841372/200265777.png)
- Here you can see in Thunderbird that I have a [email protected] account currently setup to use an IMAP Mail Server.
- In Thunderbird navigate to Tools > Account Settings
- Click on Account Actions and then Add Mail Account…
- Fill in your email account settings, then click Continue
- Now select POP3 (keep mail on your computer) and click Done
- Now back on the Account Settings window, click on the newly created [email protected] account, and update the Account Name to append (POP3) on the end, so we know which account is which easily, then click OK
- At this point you can now see that our original IMAP account has 5 messages in it, and these are stored on the server.If you attempt to login to webmail at this point, you’ll see these same messages stored there.
- You can select one of the messages from your IMAP account, then hit Ctrl-A to select all messages, then drag them into your POP3 account to move these messages off the server.Now if you login to webmail, you’ll see all those messages have been removed from the server.
- Now you’ll want to remove your IMAP account from Thunderbird to ensure that it doesn’t keep trying to make a duplicate connection to the server, since your POP3 account is already going to connect and retrieve your email.Right-click on the IMAP account and click on Settings…On the Account Settings window, click on Account Actions and then Remove Account.You’ll get a confirmation window pop-up asking if you’re sure you want to remove the account, just click OK.
Switch from POP3 to IMAP
Switching a POP3 account to IMAP allows you to keep messages on the server, and to syncronize them to multiple IMAP clients. You just need to create a new IMAP account in your mail client, then drag any messages from your old POP3 account into the IMAP account if you’d like to retain them and remove the POP3 account.
While IMAP might be more convenient for how you check email, because all of your messages get left on the server instead of your local mail client it could potentially lead to IMAP resource usage problems.
- Here you can see in Thunderbird that I have a [email protected] account currently setup to use a POP Mail Server or POP3.
- In Thunderbird navigate to Tools > Account Settings
- Click on Account Actions and then Add Mail Account…
- Fill in your email account settings, then click Continue
- Now select IMAP (remote folders) and click Done
- Now back on the Account Settings window, click on the newly created [email protected] account, and update the Account Name to append (IMAP) on the end, so we know which account is which easily, then click OK
- At this point you can now see that our original POP3 account has 5 messages in it, and these are stored on the local computer itself.If you attempt to login to webmail at this point, you’ll see there are no messages stored on the server for this account. This is because they are all stored locally in your mail client.
- You can select one of the messages from your POP3 account, then hit Ctrl-A to select all messages, then drag them into your IMAP account to move these messages to the server.Now if you login to webmail, you’ll see all those messages you just moved on the server-side. They can now be syncronized to any IMAP client such as your phone without the messages being removed from the server.
- Next you’ll want to remove your POP3 account from Thunderbird otherwise the messages in your IMAP account will keep being removed from the server and pulled back into the POP3 account.Right-click on the POP3 account and click on Settings…On the Account Settings window, click on Account Actions and then Remove Account.You’ll get a confirmation window pop-up asking if you’re sure you want to remove the account, just click OK.
You should now have the knowledge and know how to switch your mail client from using either POP3 or IMAP as your prefered email retrieving protocol.