How to send jpg in subject line of email

Question

Using php is it possible to send a jpg in the subject line of an email? I've noticed there are limited ways to send emolji

Answer 1

Not possible to add graphics like jpg, png or any other file format to the subject of a mail. Neither emojis.

The mail client can change some characters to emoji, for user friendly.

The mail client for example can change the <3 by a heart or :) by a smile face.

you cannot add it to the subject, just add this char and pray for the client change those chars.