Email Bounces

What is a Bounce?

Bounces occur when a message cannot be delivered to the email address of the recipient. There are many reasons for a bounce to occur, and these are separated into two broad groups: 
  • Hard Bounces: A hard bounce indicates a permanent failure which is not likely to be resolved with a resend. Hard bounces are most often caused by non-existent email addresses.
  • Soft Bounces: A soft bounce indicates a transient failure. It is likely that the email address is valid but other temporary conditions have caused a delay in delivery. Soft bounces are commonly caused by email inboxes being full, or addresses being suspended.

Bounce Descriptions

Each bounced message is tracked in the Bulk Email Interactions. Here you can see the exact message returned from the receiving email server. This will indicate the reason for the bounce. Some examples are shown below:

Soft Bounce Examples:

bounce_fm: {mta_relay} host []:25 said: 552 5.2.2 <> Mailbox has exceeded the limit (in reply to RCPT TO command)
This indicates that the mailbox is full and the message could not be delivered.
bounce_tr: {mta_relay} host[]:25 said: 550 5.2.1 The email account that you tried to reach is disabled. p28si19674740ybk.52 (in reply to RCPT TO command)
This indicates that the email account has been disabled temporarily. This is sometimes due to suspension from an Internet Service Provider.

Soft Bounce Management

Soft bounces are tracked as interactions and can be used to add records back to an Outreach List for resending.

Hard Bounce Examples:

bounce_hb: {mta_relay} host[]:25 said: 550 No such recipient (in reply to RCPT TO command)
This indicates that the email address is unknown.
bounce_df: {mta_relay} domain name does not exist (
This indicates that the address in invalid due to a non-existent domain name.

Hard Bounce Management

Once a Hard Bounce returned, the Person to whom the email is attached is automatically Unsubscribed from future mailings. This is evident on the Person record by going to the Administration area under Contact Methods. You'll see Bulk Email radial  set to 'Do Not Allow'. No further action is required for this record but if a new email address is entered, the status can be changed allowing the Person to receive bulk mail again.