Where is my trash from emails

[cdal1]

I accidentally deleted an email the other day and can't find it. I looked on the trash folder on my pc and iPhone and both are empty. The settings on my iPhone for trash is set to on server. Any help would be greatly appreciated
thanks

 

[freediverdude]

What email service is it? I know with Yahoo typically it gets deleted every week or so from the trash. There's also a thing between my mac's Mail program and Yahoo, where it deletes the older emails off of Yahoo's servers once they're downloaded to the Mail program. If I look up my Yahoo mail on the web, there's typically only a few week's worth on there because of that.