Email messages can be deployed in one of three formats: Plain Text, HTML, Multipart MIME. When you deploy a message, a fourth option allows you to let Contacts determine the format they wish to receive.
| Email Format | Number | Text | Description |
| Plain Text | 1 | plain | Text only with no formatting other than the use of line breaks and spacing. |
| HTML | 2 | html | Rich text content supports images, font sizes, colors. |
| Multipart MIME | 99 | mime | Both HTML and Plain Text merged into one message. Contacts will automatically see the content in the format their email client is set to display. |
| Contacts Selected | na | na | The format defined in the Contact's subscription record for the List specified. Subscriptions default to the Plain Text format. Only use this option if you have allowed Contacts to define their preferred format or you have imported your List and defined the format upon import. |