Why ?

So why another MUA (mail user agent)?
– I really need tabbed messaging, so I can leave messages I have to deal with open inside mail client and not cluttering task bar.
– finally rewrite is stable enough to start writing the features I thought of in 2004
– I kinda get acustomized to the client I wrote, so thats why I won’t switch to Thunderbird which I consider as only alternative,
– I’m adding new features as I need them or people I know need them.
– I’m adding unique security features to client to protect classic users
– I have got an idea, of some features that would make si.Mail unique, but that would require complete rewrite of application.
Some shortcomings I found in the ones that I tested.
– They have big download size e.g. more than 2MiB. I’m still on dial up, so size matters.
– You cannot tell them where to store messages,
– Character set is fixed to iso-8859-1 which is useless here,
– They don’t support text/html part of message or if they do, they are really really unsafe, …

si.Mail unique, or si.Mail was first with that feature

  • mailbox that shows messages from last 24hrs
  • view messages in tabs
  • automatic message classification by (on TO DO since beginning of 2004, but needed complete rewrite) by: (can be disabled to make interface simpler)
    • Favorites: mark mailbox as favorite in any view it will be displayed here. (Recommended mailboxes: Sandbox, To Do, Today, Yesterday, This week, Previous week, Unread. So there is almost no need to leave Favorite view)
    • Correspondent: messages you sent or get from a person your e-mail MUST be in To: or CC: header, you can than later combine correspondent folders, so yo ucan group messages form all e-mails one person has into single mailbox
    • Category: you can assign unlimited number of categories to each message. Excellent for organizing messages when working on projects.
    • Date: messages sorted by sent date. Sorted into Year\Month structures. Includes 4 additional mailboxes: Today, Yesterday, This week, Previous week, which show messages as their name suggests
    • Status: with next mailboxes:
      • Sandbox:has two options it contains only messages marked with Sandbox flag, or other default option, it behaves like Inbox, with one exception if you use Delete on messages in Sandbox, messages only get removed from mailbox and not really deleted, Shift+Delete deletes permanently. The main purpose of this mailbox is to leave in it only messages you have to do something on them. e.g reply, forward, do some other work,…
      • To Do: messages you marked with To Do (priority 1-5)
      • Important, Very important: messages with header flag set to: Important, Very important
      • Annotated: messages with your comment
      • Unread: unread messages
      • Protected: messages protected from deletion
    • Attachment: messages sorted to mailboxes corresponding to attached file extensions.


  • Published under GPL (you don’t have to pay for it if you are using it, full source code availability),
  • Localization,
  • Html message view,
  • MAPI, e-mail aliases support
  • Control downloading of images, executing scripts, using ActiveX contros in html messages,
  • Theme support,
  • POP3, SMTP, SMTP AUTH, IMAP*, NTLM support for both POP3 and SMTP(yahoo, hotmail,…)* access through plug-ins,
  • Multiple account support,
  • Preview mail on Server,
  • Automatic attachment compression,
  • Colorize possible dangerous extensions,
  • Remove of dangerous html tags before putting message to html viewer,
  • Multiple profile support under one Windows account(profile),
  • Plug-in support for importing and exporting of messages and address book,
  • Use anti-virus application to verify attached files before open/save
  • SSL & TSL connection,…
  • Use plug-ins and view / print attached files directly from si.Mail
  • store attachments in separate folder, so messages file can be smaller up to 33%
  • advanced message search
  • advanced pre-download, after-download and after-send filters
  • RSS, Atom feeds support
  • Minimize to system tray
  • Portable, just copy full si.Mail folder to USB stick and go with your messages anywhere
  • Automatic message classification (read description above) (can be disabled to lower memory consumption and make interface simpler)
  • Calendar and task management supported (can be disabled to lower memory consumption and make interface simpler)
  • + a lot more, you can see some features with screenshots and description here

objects marked with * are not yet implemented

Minimum system requirements

  • Celeron 400MHz, or AMD K6 400MHz,
  • Windows 2000, XP, 2003, Vista
  • IE 6.0 or newer,
  • 13MiB of free disk space,
  • 256MiB of system RAM,
  • Screen resolution 800×600 @ 24 bit colors.

Recommended system requirements

  • 1.6GHz Pentium 4 or Athlon 1600+,
  • Windows 2000, XP, 2003, Vista
  • IE 6.0 or newer,
  • 13MiB of free disk space,
  • 512MiB of system RAM,
  • Screen resolution 1024×768 @ 32 bit colors.