How to create my own subjects depending on my forms ( contact form, application form, etc )?
If you want to completely replace the subject with your own unique subject
<input type="hidden" name="custom_apcf_subject" value="your own unique subject">
If you want to add your own subject to the default subject, "You got a mail.[via All Post Contact Form] IP-address of the sender"
<input type="hidden" name="custom_apcf_subject_sub" value="your own unique subject">
( 2019/September/09, 23:05:55, JST )