If you are sending emails that contain a foreign language, it is likely that you are using special characters that may not render correctly in the email inbox.

For example:

Olá Mundo

May render in the inbox as:

Olá Mundo

Solution

1. Convert all special characters to HTML entities.  You can use an HTML Character Converter such as provided by Email on Acid.

   For example:

   Olá Mundo

   Should be converted to:

   Olá Mundo

2. Alternatively you can add the following code to the first line of your HTML document:

   <?xml encoding="utf-8" ?>