Emojis and symbols are very popular for use in Subject lines and Preheaders. Delivra's software will support the use of them. To use these characters, simply paste the Emoji or symbol unicode into the Subject line field or Preheader field. As always, it's important to test the rendering of these characters across different email clients, as not all email clients will honor the characters.
Websites where you can find emoji and symbol characters:
If you are trying to add an accent above a letter, á for example, Outlook 2003 and earlier along with Lotus Notes will display an odd character.
Delivra supports unicode symbols and emoji. "Unicode" is the computing industry standard for text. Here is a good example of how some emoji's render depending on the platform: https://apps.timwhitlock.info/emoji/tables/unicode