So I was sitting here this morning trying to think about what would be a good thing to write about. There are so many topics its ridiculous. Should I go sales, marketing and product offering or should I go techy or just go insane. Not sure which is easier. Well I decided to do a little informative techy article on email protocols. Fun right? Maybe not in a general sense but might be if it was something you have been curious about.
So there are several ways in which to get your email. 99% of the time we don’t care we just want your email. But what makes email work? How does your computer get your email? Well you have two main components – your email client and the email server. Your email client will consist of MS Outlook, Outlook Express, Thunderbird, Mac Mail, Webmail (this is a client that generally resides on the mail server), etc. The email server well is just that its the server. It can be MS Exchange, Exim and any number of other server software.
So how does the client software connect to the server. Well you have IMAP, POP3, SMTP and MAPI. Here’s a explanation of each of the email protocols:
- POP – is the older design, and hails from an era when intermittent connection via modem (dial-up) was the norm. POP allows users to retrieve email when connected, and then act on the retrieved messages without needing to stay “on-line.” This is an important benefit when connection charges are expensive. The basic POP procedure is to retrieve all inbound messages for storage on the client, delete them on server, and then disconnect. (The email server functions like a mailbox at the Post Office — a temporary holding area until mail gets to its final destination, your computer.)Outbound mail is generated on the client, and held for transmission to the email server until the next time the user’s connection is active. After it’s uploaded, the server forwards the outgoing mail to other email servers, until it reaches its final destination.Most POP clients also provide an option to leave copies of email on the server. In this case, messages are only removed from the server when greater than a certain “age” or when they have been explicitly deleted on the client. It’s the copies on the client that are considered the “real” ones, however, with those left on the server merely temporary backups.
- IMAP – is the newer protocol and oriented toward a “connected” mode of operation. The standard IMAP procedure is to leave messages on the server instead of retrieving copies, so email is only accessible when “on-line.”IMAP is more suited to a world of always-on connections, particularly the fast connections offered by broadband mechanisms. Having to be connected to read your email is a trivial obstacle when the connection is always available. (It’s a little like leaving your messages at the Post Office, and going there every time you want to read them. That might be difficult in the physical world, but it’s easy in the virtual one.)Because messages remain on the server, until explicitly deleted by the user, they can be accessed by multiple client computers — an important advantage when you use more than one computer to check your email.IMAP does not preclude keeping copies on the client, but, in an inversion of the way POP works, it’s the server’s copies that are considered the “real” ones. That offers an important security benefit — you won’t lose your email if, for some reason, your client computer’s storage media fails.IMAP has other advantages over POP (which I will detail in another post later). It is the standard we recommend if you can’t use MAPI.
- SMTP – At the risk of overloading you with information, you should know that strictly speaking it’s only the incoming mail that is handled by a POP or IMAP protocol. Outgoing mail for both POP and IMAP clients uses the Simple Mail Transfer Protocol (SMTP).When you set up a POP or IMAP email account on email client software, you must specify the name of the (POP or IMAP) mail server computer for incoming mail. You must also specify the name of the (SMTP) server computer for outgoing mail. These names are typically in the same form as Web addresses (e.g., “mail.yourdomainname.com”). Depending on the client, there may also be specifications for email directories and searching.
- MAPI – is Microsoft’s proprietary email protocol. It provides greater functionality than IMAP for Outlook email clients interacting with an Exchange email server. It doesn’t work for anything else. (In Outlook you may simply see the connection option “Microsoft Exchange Server” rather than MAPI. It’s offering the same thing.)Remote access using MAPI may require use of a VPN connection, because the ports (communications channels) that MAPI uses are otherwise blocked for security reasons.
- WEBMAIL – Many email systems can now be accessed using only a Web browser. There is no need to install client email software of any kind. Logically, Web browser interfaces to email are like IMAP, in that all the messages remain on the server unless explicitly deleted. (Message copies can be saved on the client computer.)
We also recommend that you use SSL where available to give you a secure connection between your client and the server. To get a secured SSL connection for your domain you must have an SSL installed. If you don’t that’s OK we offer a shared SSL connection for all our customers. Just open a support ticket and we will get you that information and instructions on how to set it up.
So hopefully that wasn’t to painful or to techy.
Have a Merry Christmas
David “DJ” Kent
Server Administration, Account Manager
Kentucky – 270 908-5004
California – 530-237-2223