Email client
An email client (alternatively spelled e-mail client; commonly known as mail client; more formally known as mail user agent or MUA; hereinafter, the Client) is any digital construct that an end-user utilizes to compose, access, and/or manage his or her emails.
The Client can also refer to mail client software. More broadly, email software may refer to all the software utilized for the Clients, mail servers, or mail exchangers. One or more Clients are usually used in order to build an email management platform.
Contents
Functions
Communication
- With regard to:
- Outgoing messages, the Clients may be designed to:
- Accept requests from end-users to compose new messages.
- Analyze requests looking for their inconsistencies and/or missing data.
- Offer end-users to correct inconsistencies and/or add the missing data.
- Transfer messages to mail servers.
- Stored messages, the Clients may be designed to:
- Accept requests from end-users to manage -- delete, arrange, label, classify -- stored messages.
- Offer end-users to confirm those changes that are setup as critical.
- Execute the requests -- delete, arrange, label, classify -- stored messages.
- Incoming messages, the Clients may be designed to:
- Accept messages from mail servers.
- Analyze messages looking for their inconsistencies and/or missing data.
- Add information about the found inconsistencies and/or missing data to the messages. This information may further be used by mail clients to combat spam.
- Display messages to end-users.
- Outgoing messages, the Clients may be designed to:
- On the one side, the Clients receive requests from and display the data to end-users. On the other side, the Clients communicate with mail servers in order to receive emails from and/or send emails to.
Mailbox management
Message composition
Encryption
Hosting
There are two major models of locating the Clients.
On-premises
- End-users may install the Clients on their devices; a common example would be an app running on one's cell phone. The POP3 protocol is commonly used for sending one's emails to and/or receiving from mail servers.
On the web
- Main wikipage: Webmail
- End-users may access the Clients that are hosted online, often, next to a mail server. The IMAP protocol is commonly used for accessing and/or managing one's emails online.
Software
General comparison
General comparison of the popular Clients Category Features Evolution Outlook Roundcube Thunderbird Zimbra Legal properties Ownership OSS Proprietary OSS OSS OSS Developer Community Microsoft Community Foundation Corporation License GPL Unknown GPL MPL YPL-like Latest release 3.32.2 2019 (16) 1.2.5 60.7.2 8.6.0 History 05/08/2019 09/24/2018 04/28/2017 06/20/2019 12/15/2014 Introduction 2000 1997 2006 2003 2005 OS Windows No Yes Cross-platform Cross-platform Cross-platform macOS No Yes Linux UNIX-like No BSD No Unix No User-client interaction UI GUI (GTK) GUI GUI GUI (XUL) GUI Bi-directional text support Yes Unknown Yes Unknown Unknown Category Features Evolution Outlook Roundcube Thunderbird Zimbra
Communication protocols
Communication protocols supported by the popular Clients Category Features Evolution Outlook Roundcube Thunderbird Zimbra IMAP IMAP4 Yes Yes Yes Yes Yes POP3 Fetch all messages Yes Yes Yes Yes Yes Selected by filter No No No No No Selected by user Yes No No No No Communication protocols other than POP3 and IMAP SMTP Yes Yes Yes Yes Yes NNTP Yes No No Yes No IPv6 Unknown Yes Unknown Yes Unknown Category Features Evolution Outlook Roundcube Thunderbird Zimbra
Integration protocols
Integration protocols supported by the popular Clients Category Features Evolution Outlook Roundcube Thunderbird Zimbra RSS 0.91 Feeds No Unknown Unknown No Unknown 1.0 Feeds No Unknown Unknown No Unknown 2.0 Feeds No Yes Unknown Yes Yes Integration protocols other than RSS IMSP No Yes Unknown Yes Yes ACAP No Yes Unknown Yes Yes ATOM Feeds No Yes Unknown Yes Yes iCalendar Yes Yes Unknown Yes Yes MAPI/RPC Yes Yes Unknown Yes Unknown CalDAV Yes No Unknown Yes Unknown CardDAV Yes No Plug-in Yes Unknown Category Features Evolution Outlook Roundcube Thunderbird Zimbra
Access
Access features in the popular Clients Category Features Evolution Outlook Roundcube Thunderbird Zimbra LDAP v2 Yes Yes Yes Partial Yes v3 Yes Unknown Yes Partial Yes Regular authentication Login Yes Yes Yes Yes Yes Plain Yes No Yes Yes Yes CRAM-HMAC MD5 Yes No Yes Yes Yes SHA1 No No Yes No Unknown RIPEMD No No Unknown No Unknown MD5 APOP Yes No Yes Yes Yes DIGEST-MD5 Yes No Yes No Unknown Other authentication MSN (NTLM) browser login Yes Yes Unknown Yes Unknown Compuserve (RPA) No No Unknown No Unknown Hardware token PKCS#11 No No Yes Yes Yes Biometric No No Unknown No Unknown SMTP Auth Yes Yes Yes Yes Yes X.509 client certificate No No Unknown Yes Unknown OAuth Unknown Unknown Unknown Yes Unknown Category Features Evolution Outlook Roundcube Thunderbird Zimbra
Security
Security features in the popular Clients Category Features Evolution Outlook Roundcube Thunderbird Zimbra SSL/TLS support Secure POP3 SSL/TLS SSL SSL/TLS SSL/TLS SSL/TLS Secure IMAP4 SSL/TLS SSL/TLS SSL/TLS SSL/TLS SSL/TLS Secure SMTP SSL/TLS SSL/TLS SSL/TLS SSL/TLS SSL/TLS Secure NNTP SSL/TLS Unknown No SSL/TLS SSL/TLS Secure LDAP SSL/TLS Unknown SSL/TLS SSL SSL/TLS SNI Unknown Unknown Unknown Yes Unknown OCSP No Unknown Unknown Yes Unknown CRL No Unknown Unknown Yes Unknown PGP support inline Yes No Unknown Yes Unknown PGP/MIME or OpenPGP Yes No Yes Yes No S/MIME support protocol Yes Yes Yes Yes Unknown OCSP Unknown Unknown Unknown Yes Unknown CRL Unknown Yes Unknown Unknown Unknown Certificates on tokens, smartcards support Unknown Yes Unknown Yes Unknown Category Features Evolution Outlook Roundcube Thunderbird Zimbra
Incoming message handling
Management of incoming messages in the popular Clients Category Features Evolution Outlook Roundcube Thunderbird Zimbra Filtering Local junk Yes Yes Yes Yes Yes Server-side junk Unknown Yes Yes Yes Yes Phishing No Yes Depends on antivirus Yes Depends on antivirus Appearance HTML email Yes Yes Yes Yes Yes UTF-8 support Yes Yes Yes Yes Yes Image blocking Yes Yes Yes Yes Yes Thread view Yes Yes Yes Yes Yes Conversation view No Yes Unknown Yes Unknown Native images preview jpeg Yes Yes Yes Yes Yes gif Yes Yes Yes Yes Yes bmp Yes Yes Yes Yes Yes png Yes Yes Yes Yes Yes Native documents preview txt Unknown Yes Yes Yes Unknown pdf Unknown Plug-in Yes Yes Unknown doc Unknown Yes Yes No Unknown xls Unknown Yes Yes No Unknown odt Unknown Yes Yes No Unknown ods Unknown Yes Yes No Unknown New mail notification ticker No Unknown Yes Unknown Unknown tray icon Yes Yes No Yes Unknown tooltip Yes Yes No Yes Unknown sound Yes Yes Yes Yes Unknown Category Features Evolution Outlook Roundcube Thunderbird Zimbra
Stored message handling
Management of stored messages in the popular Clients Category Features Evolution Outlook Roundcube Thunderbird Zimbra Label messages with colors Yes Yes Yes Yes Yes with flag Yes Yes Yes Yes Yes antidelete Unknown No Yes Unknown Yes add note Unknown Yes Yes Unknown Yes Reformat received messages edit headers (e.g., Subject) No Yes Unknown Plug-in Unknown forced recode Unknown Unknown Unknown Unknown Unknown IMAP Search Yes Yes Yes Yes Yes IDLE Yes Yes Unknown Yes Yes Folders Customizable interface Partial Yes Yes Yes Yes Customizable keybindings Yes Yes Yes Unknown Yes Fragmented messages Yes Unknown Unknown No Yes Database search with regular expressions support Yes Unknown Unknown Unknown Yes Indexed search Yes Yes Unknown Yes Yes Search folders Yes Yes Yes Yes Yes Database Message file format maildir, mbox, MH Proprietary eml, VCard mbox, maildir zmmailbox Encrypted database No Yes Unknown No No Virtual folders Yes Yes Unknown Yes Yes Scheduled backup No Yes Unknown Unknown Yes Category Features Evolution Outlook Roundcube Thunderbird Zimbra
Outgoing message handling
Management of outgoing messages in the popular Clients Category Features Evolution Outlook Roundcube Thunderbird Zimbra Composing messages Spell checking Yes Yes Yes Yes Yes Signatures Yes Yes Yes Yes Yes Bottom-posts replies Unknown No Unknown Yes Unknown Message templates new Yes Yes Yes Yes Yes reply Yes Yes Yes Yes Yes forward Yes Yes Yes Yes Yes read confirmation Yes Yes Yes Yes Yes save Yes No Yes Yes Yes print Yes No Yes Yes Yes Individual for Unknown Unknown Unknown Profile Any Support in message templates scripts, programming languages JavaScript Unknown Unknown No Yes No VBScript Unknown Unknown No Unknown No PHP Scripts Unknown Unknown No Unknown No Python Unknown Unknown No Unknown No Regular expressions Unknown Unknown No Unknown No Java Unknown Unknown No Unknown Unknown Scheduling Postpone/scheduled message sending Unknown Yes Unknown Yes Unknown Category Features Evolution Outlook Roundcube Thunderbird Zimbra
