• SMTP settings allow you to send email from email applications.checking email image by Jake Hellbach from Fotolia.com
  
  Sometimes email accounts fail to work properly. This may be because an email account lacks the settings it needs to interact with your email server. Email protocols are tools that allow you to send and receive email in a desktop email application. Some of these email programs offer you a choice in which protocol you may use. As a result, learning more about the most common email protocols makes it easier to choose the one that best suits your needs.
  
  

Simple Mail Transfer Protocol (SMTP)

• The SMTP protocol is dedicated to handling outgoing mail. It won’t help you retrieve mail. Entering SMTP settings is a requirement for sending mail from a desktop email application. You have only one outgoing mail protocol to choose from, but this is not the case for incoming mail.
  
  

Post Office Protocol (POP)

• A recent release of a Post Office Protocol that enables email retrieval is version 3, which is also called POP3. This protocol supports downloading your email from a remote server. Most POP users have an option to leave copies of emails on the originating server, too.
  
  Setting up your email application to support POP3 allows you to download email and read it while you are offline. The protocol design’s history is linked to when intermittent modem connections were common. Choose this protocol when you’re trying to avoid connection charges. POP3 is also beneficial for those who may lack a stable connection to an email server.
  
  

Internet Message Access Protocol (IMAP)

• This protocol’s latest release is version 4, so it is commonly known as IMAP4. IMAP4 opens a way for you to view email messages as they reside on a remote server. You must be online to read your email. This protocol does not make emails viewable offline.
  
  IMAP4 is ideal for users who maintain a constant Internet connection. It’s also a powerful tool when multiple users need to gain access to emails. Because IMAP4 email messages stay put on the server, you can also use this protocol for checking email on different computers.
  
  

Messaging Application Programming Interface (MAPI)

• MAPI is a proprietary protocol, which means it is for use with one company’s email applications: Microsoft. As a result, you will find the option in Microsoft email client and server software. As a proprietary protocol, the MAPI option limits you to using Microsoft email applications.