What is a Hard Bounce?

Happening to even the best of email marketers, hard bounces can be extremely frustrating.

What is a bounce?

Mailing servers, both outgoing (FeedBlitz) and incoming (your subscribers) talk to each other with short messages before and during the exchange of an email. If servers were people, it’d look like:



Is Bob there? I’ve got a message for him.


That’s when everything works as it should. Sometimes though, Bob is not going to get the email.



Is Bob there? I’ve got a message for him.

Hmm, Bob’s mailbox is full, try again later.

This indicates the problem is temporary.




Is Bob there? I’ve got a message for him.

Sorry, Bob doesn’t exist.

This would happen if the problem were permanent.

A hard bounce occurs if:

  • FeedBlitz attempts to send an email and receives a permanent failure message from the subscriber’s internet service provider in return

  • FeedBlitz email servers received a temporary failure message repeatedly from  subscriber’s inbox after an established, standard set of contact attempts.

When an email returns as undeliverable, we will continue mailing the email address for a period of two weeks or three subsequent mailings, whichever time frame is longer. Once these contact attempts have been exhausted, the email address will be classified as a hard bounce and removed from your list of subscribers.

Why remove the email address if it bounces?

Email addresses returned as hard bounces are removed to protect the sending reputation of all FeedBlitz publishers. When an email service provider continues to send to an email address that has returned as bad or invalid, it will cause a series of red flags, eventually blacklisting the sender. FeedBlitz closely monitors both hard and soft bounces, removing emails when necessary, to prevent possible blacklisting.

In other words, we do it all for the sake of your reputation! (Ok, we do it for ours, too.)

What’s the difference in a soft and a hard bounce?

When an email address is temporarily unavailable, or the mailbox is full, resulting in a mailing not being delivered, it is referred to as a soft bounce. A soft bounce turns into a hard bounce once the contact threshold of two weeks or three subsequent mailings has been passed, with zero successful attempts in reaching the email address.

Why do emails bounce?

Hard bounces (and soft bounces) can be the result of a variety of factors such as:

  • Email address no longer exists

  • Stricter spam filtering

  • Invalid domains or typos

  • Blocking of FeedBlitz mail servers *We constantly monitor all major email providers (Gmail, Yahoo, Hotmail etc) and address these rare issues immediately.

Can I prevent hard bounces from happening?

While hard bounces are often unavoidable, there are a few steps you as the publisher can take to ensure the greatest likelihood of your emails being received.

  1. Encourage your subscribers to have the email address feedblitz@mail.feedblitz.com added to their whitelist of approved senders. (Note: We recommend they do this in the activation email received after subscribing to your site!) If a large number, 10+, belonging to the same, personalized, domain are returned as hard bounces, the subscribers will need to contact their IT department have the domain holders whitelist our FeedBlitz servers. This can happen in cases such as business-related email addresses.

  1. Have a personalized @sitedomain email address as your sending email. Using @aol, @yahoo or even @gmail can prevent emails from reaching inboxes properly. While FeedBlitz takes great measures and precautions to avoid this from occurring, you can greater ensure proper delivery by editing your sending email address.

Want More Information? You may remember a previous post regarding recent DMARC changes in Gmail. As we did similarly with AOL and Yahoo, our development team put safety precautions in place well before these changes went into effect. You can read more about that here.

At FeedBlitz we use multiple email servers to deliver your emails at any given mailing. Should we notice an ISP having trouble sending from a server, all mailings will be rerouted through another server while the issue is addressed. This all takes place behind the scenes, with zero to little disruption in email distribution.

What do I do after a hard bounce?

FeedBlitz publishers are able to receive summary emails regarding subscription and unsubscription information for their lists, these automated notifications show any potential hard or soft bounces experienced during mailings.

Should you notice a hard bounce has occurred on a valid email address, you are welcome to contact that address to encourage adding feedblitz@mail.feedblitz.com to their whitelist of approved senders. This typically resolves the issue.

Corporate Email Addresses: If a large number of addresses (20+) all associated with the same domain name are returned as hard bounces, an individual of that domain will need to contact their IT department to have FeedBlitz added as an approved sender.

Mainstream ISP providers such as Yahoo, Gmail or Apple mail, FeedBlitz Support are monitored and FeedBlitz will investigate issues associated with abnormally high bounce rates.

All other issues are evaluated on a case by case basis, once a publisher has exhausted all initial contact and whitelisting attempts.

If you have further questions on hard bounces, send our Support Team an email at support@feedblitz.com, chat, check out our Help Forum, or give us a call at 1.877.692.5489. Our Support and Sales Desk is available Monday – Friday from 9 am to 5 pm EST.


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