These are both types of email account (Microsoft Exchange is another), and are the most common variety.
In simplest terms, an email is sent to you and sits on the server, waiting for you to login; turn on your email program; or check your mobile to see it. The biggest difference is that:
- POP3 downloads it fully to your computer, removes it from the server when you or your computer does Send/Receive
- IMAP4 downloads a copy (or the start of and more when you click) – also no need to Send/Receive anymore
Deleting Differences
If you delete an email using POP3, then you have downloaded the email and it is fully deleted. On IMAP4 (depending on the device) you might just see it marked as ready for deletion, i.e. with a strikethrough (iPhones make it disappear but actually only mark for deletion). You then need to ‘Purge’ the items marked for deletion.
In Microsoft Outlook this can be a bit hidden (under the Edit menu), so a tip for older versions (that don’t have the new ‘ribbon’) is to choose ‘Tools > Customize’ and then go back to the edit menu (while the pop-up window is there) and drag the ‘Purge’ button onto the main toolbar. It will save you oodles of time!
Online Folders with IMAP (within limits)
You can also choose to make some folders online for your emails if using IMAP. This can be really handy, especially if sometimes looking at your email through a web browser. These should then synchronize to all your devices automatically, though you might find you have to ‘subscribe’ to the folders in your Email Client/Program (right-click on the account usually). They can take a couple hours or restarts to fully appear.
These folders can usually be seen by clicking on the + sign to the left of your email account name. This can also be a little confusing as you will still often have a normal ‘Personal Inbox’ (Outlook particularly) but now you have a new ‘Inbox’ which is online, your ‘Personal Inbox’ is just on your computer.
Please do remember though that your IMAP account will have normally have a size-limit and hence we would recommend to keep a few simple folders online but if the email needs a folder then it should really be fully downloaded into your normal folder structure. A little cleanliness with your emails goes a long way!
When Do I Choose?
This choice needs to be made when you add the email account to your computers. This is true of pretty much any device or computer as they have to connect in a different way to the server, i.e. an always-on active connection. For some devices, eg. an iPhone, you need to choose ‘Other’ to set it up.
Tip: If you keep seeing ‘server timeout’ or something similar then under somewhere like ‘Advanced’ when editing your email accounts you can reduce the frequency of checking from once a minute to once every 5-10 minutes. This helps especially if you have multiple devices checking at once (Laptop, Desktop & Phone).
