What does "550 internal oob The recipient is invalid" mean ? ...... Hard Bounce / Soft Bounce ?

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Anonymous
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What does "550 internal oob The recipient is invalid" mean ? ...... Hard Bounce / Soft Bounce ?

We have had a return of nearly 2000 bounces from a recent email send that are appearing in our bounced email smartlist; so hard bounces. Looking at the reason codes, there are numerous, but one is 550 [internal] [oob] The recipient is invalid.

I am sure that some of these arent valid hard bounces but rather spam. One of our agents has been in regular email contact with a customer via outlook, but this same customer has come back via marketo as 550 [internal] [oob] The recipient is invalid.

Another one we have, under the same scenario as above, being emailed via outlook has returned via marketo with 550 5.1.1 User Unknown.

If anyone has any ideas or ways we can move forward, I would be really grateful as currently Marketo wont send to these people again but we know that some are indeed valid contacts.

Thanks 🙂
7 REPLIES 7
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Level 6 - Champion Alumni

Re: What does "550 internal oob The recipient is invalid" mean ? ...... Hard Bounce / Soft Bounce ?

Alice, here is a great document created by a couple of Marketo employees that you might find helpful: Anaylzing Email Deliverability. I think those are hard bounces but the 8-page document will answer more for you.
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Level 2

Re: What does "550 internal oob The recipient is invalid" mean ? ...... Hard Bounce / Soft Bounce ?

Hi Adam,

The document is not available, can you please share it again.

Thanks...

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Re: What does "550 internal oob The recipient is invalid" mean ? ...... Hard Bounce / Soft Bounce ?

Hi Alice, as Adam has suggested, these email addresses are not correct for some reason. Is it possible that they've been added to Marketo with errors (not sure what CRM you're using)? Recipient is invalid isn't typically used to identify spam as far as I've seen in the past. 
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Re: What does "550 internal oob The recipient is invalid" mean ? ...... Hard Bounce / Soft Bounce ?

Hi Alice, if you feel your list is good there could have been a character that caused the upload error.  Great example is a space before the email address.  If you have tick marks, Marketo will warn you of the error.
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Level 10 - Champion Alumni

Re: What does "550 internal oob The recipient is invalid" mean ? ...... Hard Bounce / Soft Bounce ?

Yep, that's what's happening. I also wrote a guide on this which helps you go through the cleanup process.
http://www.slideshare.net/jdavidhill/marketo-email-reputation-management?related=1
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Anonymous
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Re: What does "550 internal oob The recipient is invalid" mean ? ...... Hard Bounce / Soft Bounce ?

Some of these email addresses cannot be wrong as our agents are sending emails via our CRM with the exact email that has synced through to Marketo, and through outlook it is being delivered. However, the email is being bounced back in Marketo. Another one where this is the case is 550 5.1.1 User Unknown

I am so confused!
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Re: What does "550 internal oob The recipient is invalid" mean ? ...... Hard Bounce / Soft Bounce ?

Alice,

These are bounces, but the telling part here is the "oob" piece of the message. This indicates that the bounce message was "Out Of Bounds", meaning that the recipient mail server first said that it would accept the email, but then afterwards bounced it. If you look at the lead records that are giving these messages, you'll see that there will be an "Email Delivered" activity right before this bounce message, which is what makes it "Out Of Bounds" since it's reporting that it both delivered it and then also that it bounced it.

This happens a lot but there isn't really any way Marketo can control it--it's entirely up to the recipient mail server. Marketo records the "delivered" or "bounced" messages back whenever they come in, but recognizes when it's gotten both that it's unusual behavior, which is why it appends that "[oob]" piece into the message.

Many times this happens when a recipient mail server takes in emails in through a main server, then dumps them over to a secondary server. The first one that takes in the email gives back the "Email Delivered" message. Then, the secondary server evaluates each email based off of spam filters and against known email addresses in their system. If they've got invalid email addresses or are filtered out as spam, they'll then be bounced, causing the bounced message after the delivered message.

If you want to track your bounces so that you don't continue to have problems, try this doc here: Maintaining a Directory of Leads Bouncing Emails