Are you sending important or unimportant things? When its unimportant or important to the receiver only, you push responsibility to them: "I sent it. Must be y

Are you sending important or unimportant things? When its unimportant or important to the receiver only, you push responsibility to them: "I sent it. Must be your email that's glithced. Tried Gmail or Proton?" When its important to you, you use your backup Gmail or Proton account.