Email Bounces: Hard Bounce v Soft Bounce

When a marketing or newsletter email is rejected by a subscriber’s email server, it’s called a bounce.

There are different types of bounces that depend on the reason the email bounced. These details can be found in your email marketing platform’s campaign reporting.

It’s a good idea to keep a close eye on your bounce numbers to be sure your campaigns are reaching your subscribers, and that you’re abiding by spam laws.

Hard Bounces

A hard bounce indicates a permanent reason an email cannot be delivered. In most cases, bounced email addresses are removed automatically and immediately from the active subscribers and generally placed in the cleaned portion of your list. Most email platforms conduct this process automatically and are then excluded from future campaigns.

While there are many reasons an email address may hard bounce, these are some common reasons this could happen.

-Recipient email address does not exist.
-Domain name does not exist.
-Recipient email server has completely blocked delivery.

There are occasionally cases in which valid email addresses can hard bounce or a subscriber could mistakenly unsubscribe and will need to opt back in to your list.

Soft Bounces

Soft bounces typically indicate a temporary delivery issue to an address and are typically handled differently than hard bounces. When an email address soft bounces, it will immediately display as a soft bounce in the campaign report.

If an email address continues to soft bounce in additional campaigns, the address will eventually be considered a hard bounce and cleaned from your list.

Platforms vary on their rules to determine when a persistent soft bounce becomes a hard bounce. The general approach is 7 to 8 soft bounces occur for an email address with no previous subscriber activity (open / click behaviour) before being seen as a permanent delivery failure and therefore a hard bounce.

It can be upwards of 15 soft bounces for subscribers with previous subscriber activity before converting a soft bounce into a hard bounce.

While there are many reasons an email address may soft bounce, these are some common reasons this could happen.

-Mailbox is full (over quota).
-Recipient email server is down or offline.
-Email message is too large.