Webmail is a web application that allow users to access their e-mail through a web browser, as an alternative to using an email client such as Microsoft Outlook, Mozilla Thunderbird or Eudora.

The most popular webmail providers are Hotmail, Yahoo! Mail and Gmail. Other webmail providers include AIM Mail, Mail.com, Fastmail and Lycos Mail. It is also possible to run webmail software on one's own web server. There are commercial webmail software such as Outlook Web Access (OWA) or Atmail as well as open source software such as Horde IMP, OpenWebmail (based on NeoMail), RoundCube or SquirrelMail. Many universities and schools use such software to provide students and staff with web-based access to their email accounts. Also, many Internet Service Providers offer webmail for their customers.

Features

Most webmail services have the following features:

• Folders
• Filtering (incoming e-mail to dispatch to related folder)
• Trash folder
• Address book

Several webmail services offer the following features:

• E-mail spam detection
• POP3 mail retrieval
• Anti-virus checking of mail attachments
• E-mail forwarding
• Dictionary and thesaurus when composing messages
• Spell checker

Advantages of Webmail Services

• E-mail is stored remotely on a server, which means that it is accessible anywhere there is an internet connection and a web browser.
• Centralised maintenance of the (Webmail) email client; upgrades and security fixes are done by the administrator. No need to install, update and patch local email clients.

Disadvantages of Webmail Services

• The user must stay online to read and write more than one e-mail. They cannot easily edit mails they are working on offline (except by copying and pasting the text).
• Commercial webmail services often offer only limited e-mail storage space and either display advertisements during use or append them to mails sent. Unlike with a local client, the user cannot keep the messages on their local hard drive.
• Most e-mails are usually short, plain text messages of less than 2 kB, but using webmail the original e-mail is wrapped in the website's HTML, which can be 40 kB or more. Obviously this brings a significant decrease in speed of use, especially on a slow network connection.
• Webmail accounts are often targets of spam.
• Webmail accounts are accused of being insecure.
• Free webmail accounts are often inaccessible to blind users, due to the use of a visual CAPTCHA.

Some webmail providers offer disposable (spam collection) e-mail addresses - examples include TrashMail and Mailinator. There are also secure webmail providers like Hushmail that do not store any personal information and send all mails with 128-bit encryption.

For providers who do not allow POP3 access a program like FreePOPs may be used with a conventional POP3 client.

Other Features of Webmail

• Webmail accounts can be set up with minimum technical competence and can provide independence from one's current ISP as well as a degree of anonymity.
• The ability to access it anywhere means it is harder to trace the individual who uses an account than if they used a connection associated with their home address.

These features mean it can in theory be more easily used as a communication tool for nefarious purposes (or for avoiding oppressive authorities) than conventional e-mail. In practice, most governments' security agencies are fairly easily able to track individuals who try to use such methods, just as with someone who calls from phone booths. Ordinary citizens will find it more difficult, however.