Whitelisting an email address:
Whitelisting means adding an email address to your email clients contact list. Example: You are receiving newsletter from Scripts4webmasters.com. To ensure proper delivery of the newsletter, you can add 'From email' address of the newsletter to your contact list. If you are an email marketer, ask your subscribers to whitelist your company email.
Blacklisting an email address:
Opposite to whitelisting (see above). You deliberately add an email address in your email client to block email from that sender. As more and more spam coming to inboxes, most people use this feature to push the unwanted emails to junk or delete them permanently.
Blacklisting an ip address:
The ip numbers from which the spam email are coming will be blocked so no email from these ips are received into the inboxes. Many services like sorbs.net, dnslb.info, spamhaus.org etc list the blacklisted ips. Email providers use these lists and if the email are coming from these ips, they will be pushed into junk folder or deleted.
Junk folder:
Junk folder is a folder in your email clients into which the spam emails get into. Unfortunately sometimes the legit email goes into the junk folders. You can also set the email filter to divert spam email into the junk folder.
As a subscriber you can whitelist an email address and make sure your newsletters are delivered to your inboxes.
Email client: (Mail User Client)
Email client is an web based or PC based software that you use to check, retrieve and read your email. Example: Microsoft Outlook, Web based Squirrelmail
Mail Transfer Agents:
Mail Transfer Agents are computer software that send and receive email messages between the computers. Example: Sendmail, Qmail, Postfix. These software are installed on servers so you can send email from your email client to them and they send messages to other MTA.
SMTP:
Simple Mail Transfer Protocol is a standard method of transfering email between the Mail Transfer Agents.
Email client (Mail User Agent) of one user sends email to Mail Transfer Agent > Via SMTP To another Mail Transfer Agent > Email client of another user retrieves.
POP/IMAP:
The Internet Message Access Protocol (IMAP) and Post Office Protocol (POP) are two standard methods to retrieve email from mail servers. Example: Your email clients like Outlook retrieve email from your web mail or hotmail and displays infront of you to read.
ISP:
Internet Service Provider is a company that provides internet connection for you to access other computers on the World wide web. You are connected to the internet through their IP numbers. So if your ISPs ip number is blacklisted, then your email will end up in the junk folder of your subscribers. So be careful and talk to your ISP about removing their ips from the blaclist sites.
Email filters:
Email filters are certain conditions in your email clients based on which your incoming email are managed. Example: If you want to delete all email coming from a certain user, you can set up an email filter, so your email client deletes them. Or if you want all your newsletters into a special folder, you can do this by setting up a email filter.
