​Soft Vs Hard Bounces

When you attempt to send out an email and it doesn’t reach the intended recipient/mail server, this is known as a bounce. Under normal circumstances, the email server will provide a reason for why a piece of mail bounces so the sender knows what went wrong on the other end. These bounces can be separated into two categories known as a soft bounce and a hard bounce. Let’s define what each of these types of bounces means.

What Is A Soft Bounce?
A soft bounce occurs when an email reaches a recipient’s mail server but gets bounced back undelivered before it reaches the intended inbox of the recipient. Soft bounces can occur when.

  • The inbox of the recipient does not have enough storage space to store the message
  • The size of the file being sent to the inbox is too large.
  • The mail server might be shut down at the time of sending.

When a soft bounce occurs, this typically will indicate that the address in question does exist but cannot be reached at the time of sending an email. A soft bounce is still harmful to your email deliverability rates since ISPs will register it as a bounce, regardless of the reason.

What Is A Hard Bounce?
A hard bounce occurs when an outgoing email fails to make contact with the intended address/mail server and cannot be delivered. A hard bounce will typically indicate that the email address in question does not exist and indicates a permanent failure to send. The reason for this could be…

  • A fake/incorrect email address
  • A fake/invalid domain
  • No email server exists under the domain

Hard bounces will directly affect your domain reputation and should be avoided at all costs. The easiest way to identify email addresses that can result in a hard bounce is to run all email lists through a verification service before attempting to make contact.