Scroll down of the email, click unsubscribe

hint:

some marketers purposely removed unsubscribe link.

i'm using gmail. you can use your equivalent of viewing the email source code and headers.

most marketing service have unsubscribe and spam report links in the email header. search for it in the email header.

if using Gmail, you may unsubscribe via Gmail too. But, most of the software provider provides unsubscribe function as this is a must....So it might be hidden some where.

I just unsub Food Panda's marketing email last few months, the link is placed bottom of the email.