The Chilkat Email component will automatically choose the best encoding and charset based on the characters used in a body. It auto-recognizes the language of characters. If a mix of languages is present, then utf-8 is chosen as the charset. Otherwise, the most commonly used charset for email for a particular language is automatically used.
Content-Transfer-Encoding: For Asian languages, base64 is the default encoding. For Western languages, quoted-printable is the default.
The Charset and transfer encoding can be manually set. To set the charset, simply set the Charset property to the name of the charset desired. For example, Japanese emails can be sent in "iso-2022-jp", "shift_jis", "euc-jp", "utf-8″, etc.
To set the content transfer encoding, call AddHeaderField("content-transfer-encoding","") to add or replace the Content-Transfer-Encoding header field, which forces a specific encoding of your choice. Here is a C# example:
Chilkat.Email email = new Chilkat.Email();
email.Subject = "à á â ã ä å";
email.Body = "à á â ã ä å";
textBox1.Text = textBox1.Text + "---- Default ----\r\n" + email.GetMime() + "\r\n\r\n";
email.AddHeaderField("content-transfer-encoding", "8bit");
textBox1.Text = textBox1.Text + "---- 8bit ----\r\n" + email.GetMime() + "\r\n\r\n";
email.AddHeaderField("content-transfer-encoding", "base64");
textBox1.Text = textBox1.Text + "---- base64 ----\r\n" + email.GetMime() + "\r\n\r\n";
email.AddHeaderField("content-transfer-encoding", "quoted-printable");
textBox1.Text = textBox1.Text + "---- quoted-printable ----\r\n" + email.GetMime() + "\r\n\r\n";
This is the program output:
---- Default ----
MIME-Version: 1.0
Date: Wed, 01 Aug 2007 16:31:24 -0500
Message-ID: <CHILKAT-MID-0f081b40-524e-fe68-1067-13feef4106ec@CK2007>
X-Mailer: Chilkat Software Inc (http://www.chilkatsoft.com)
X-Priority: 3 (Normal)
Content-Type: text/plain;
charset="iso-8859-1"
Subject: =?iso-8859-1?Q?=E0_=E1_=E2_=E3_=E4_=E5?=
Content-Transfer-Encoding: quoted-printable
=E0 =E1 =E2 =E3 =E4 =E5
---- 8bit ----
MIME-Version: 1.0
Date: Wed, 01 Aug 2007 16:31:24 -0500
Message-ID: <CHILKAT-MID-0f081b40-524e-fe68-1067-13feef4106ec@CK2007>
X-Mailer: Chilkat Software Inc (http://www.chilkatsoft.com)
X-Priority: 3 (Normal)
Content-Type: text/plain;
charset="iso-8859-1"
Subject: =?iso-8859-1?Q?=E0_=E1_=E2_=E3_=E4_=E5?=
Content-Transfer-Encoding: 8bit
à á â ã ä å
---- base64 ----
MIME-Version: 1.0
Date: Wed, 01 Aug 2007 16:31:24 -0500
Message-ID: <CHILKAT-MID-0f081b40-524e-fe68-1067-13feef4106ec@CK2007>
X-Mailer: Chilkat Software Inc (http://www.chilkatsoft.com)
X-Priority: 3 (Normal)
Content-Type: text/plain;
charset="iso-8859-1"
Subject: =?iso-8859-1?Q?=E0_=E1_=E2_=E3_=E4_=E5?=
Content-Transfer-Encoding: base64
4CDhIOIg4yDkIOU=
---- quoted-printable ----
MIME-Version: 1.0
Date: Wed, 01 Aug 2007 16:31:24 -0500
Message-ID: <CHILKAT-MID-0f081b40-524e-fe68-1067-13feef4106ec@CK2007>
X-Mailer: Chilkat Software Inc (http://www.chilkatsoft.com)
X-Priority: 3 (Normal)
Content-Type: text/plain;
charset="iso-8859-1"
Subject: =?iso-8859-1?Q?=E0_=E1_=E2_=E3_=E4_=E5?=
Content-Transfer-Encoding: quoted-printable
=E0 =E1 =E2 =E3 =E4 =E5
