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Pro Long term support and development
Goichi Hirakawa, the main developer of GyazMail, has been committed to his project since 2003 and delivers updates regularly.
Pro Mail sorting rules
The user can define complex mail sorting rules for incoming and outgoing mail.
Pro 64-bit support
As of v1.6
Pro Native Cocoa API based
GyazMail is a native macOS application, based on the Cocoa API.
Pro customizable fonts & colors
the mailbox view is very comfortable
Pro Very good support for Asian languages
GyazMail is a Japanese product, so it has very good support for Asian languages.
Pro Supports older versions of macOS
GyazMail is available for all versions of Mac OS X / macOS starting with version 10.1
Pro Freely selectable hard line wrap
In GyazMail you can set a maximum number of characters per line. The program will wrap the lines using hard wrapping on sending. This feature is very useful for newsgroups that require a hard break after 72 characters.
Pro Supports a big variety of character encodings
Uses Oniguruma regular expression library, which is a very elaborate regular expression engine that supports a big variety of character encodings. This makes very much sense with e-mail, as in an e-mail theoretically any character encoding could be used. Because it is free software (BSD), written in C, very elaborate, stable and still actively maintained it is also used in Atom, Take Command Console, Tera Term, TextMate, Sublime Text, SubEthaEdit, and jq.