Shitmail is described as 'Tired of receiving spam in your mailbox? This only happened because you inserted someday your email address on some shitty sites'. There are more than 50 alternatives to Shitmail, not only websites but also apps for a variety of platforms, including Windows, Firefox, Linux and Google Chrome. The best alternative is MailDrop, which is both free and Open Source. Other great sites and apps similar to Shitmail are Spamgourmet (Free, Open Source), 10 Minute Mail (Free), Burner Mail (Freemium) and Mailinator (Freemium).
Rain Mail is free temporary email service, you can create a free temp email address to use for registrations on social media or newsletters etc. addresses are valid forever but are public and emails are deleted after 24 hours.
FakeMail is a free temporary email address generator and throwaway email service provider offering temporary, secure, anonymous, free, disposable email addresses where you can receive email temporarily but self-destructs after a certain time.
Minute Mailbox is a temporary email service that allows you to generate email IDs and receive emails right the way. You can get your temporary addresses for free with a click of the mouse and let them self-destruct after 24 hours.