CalMail language settings

A potential problem

The default web browser client for CalMail is SquirrelMail. The default language in SquirrelMail is English. With that default setting the text messages you compose will have

Content-Type: text/plain;charset=iso-8859-1

in their header irrespective of whether your message or a portion of it may contain higher Unicode glyphs (e.g., Central European, Cyrillic, Greek, Hebrew,...). This will cause a number of mail clients to display your message incorrectly, including SquirrelMail itself which will display your message in the Sent folder filled with garbage HTML macros for each higher Unicode glyph you entered.

Solution

Change your language in Options > Language to any language but English (e.g., to British, Polish, Russian,...). Now all your text messages will be sent with the directive

Content-Type: text/plain;charset=utf-8

which ensures that basically any mail client will display the text of your message correctly, including CalMail's own SquirrelMail that will now correctly display your message in the Sent folder.

Changing the default language English to another language in Options has also the visible effect of several buttons now carrying labels in that language; the same with some messages. If you prefer to keep those labels and messages in English switch the language option from English to British.

An alternative is to use RoundCube mail client (the link provided on the CalMail web page). RoundCube sends all your plain text messages with

Content-Type: text/plain;charset=utf-8

whether your selected language is English (the default), or any other one.

Note that in the RoundCube the default mode when you compose a message is HTML mark-up, but you can always switch to the plain text mode by pressing the corresponding button in the Compose window.