Soft Bounce and Auto-Reply

[Michael_Florin]

Hello all!

I just noticed a pretty substantial amount of emails being marked as Soft Bounced with these details:

"550 [internal] [oob] The message is an auto-reply/vacation mail."

I checked and all emails with these bounce details were also marked as "Delivered".

And now I'm wondering: Shouldn't "Delivered" and "Bounced" be mutually exclusive? Or does this specific error message mean that this email did in fact never hit the inbox? And how is that represented on Email Performance Reports, where "Sent minus Bounces = Delivered"?

I'm also seeing that this idea exists - https://nation.marketo.com/t5/ideas/reclassify-out-of-office-soft-bounce-replies/idi-p/301120 - but it doesn't seem to bother too many people. Why not? 😉

Thanks!
Michael

[Darshil_Shah1 · Accepted solution]

Well, per my understanding when you send email to people who have out of office or auto-reply messages turned on, the auto-reply gets sent back from recipient's mail server when the email is delivered from Marketo which triggers a “Vacation/Auto-Reply” bounce. The email has been delivered to the recipient(s) in this case, just that they may take a while to see / interact with the email as they're probably OOO. 

Since the email has been delivered to the person hence Marketo logs the Email Delivered activity in the activity log. I think this may be one of the rare cases where the email delivered and soft bounced are not mutually exclusive activities for an email send.

There could be number of reasons that this has been of little interest to people -

a) Not everyone may be diving deep in to analyzing the soft bounces (unless the number is surprisingly high), and/or

b) People may not be encountering this a lot in their instance

[Oz_Platero]

Hello @Michael_Florin 

And now I'm wondering: Shouldn't "Delivered" and "Bounced" be mutually exclusive?

* To answer your question: No they are not mutually exclusive.  While working for Marketo support years back I have seen cases where email is delivered, then later a Hard Bounce Cat 2 comes back.

[Michael_Florin]

Thank you all!

I don't particularly like this scenario, but at least I know what I'm dealing with. 🙂

[SanfordWhiteman]

The main thing that’s confusing here is the use of the term Soft Bounce and the SMTP 550 error code. These both suggest something more serious happened.

I think the behavior is okay given the 2 choices of “pretend nothing happened at all” and “say something interesting happened even if you mislabel it as bad.” But it would be far better if we had an Out-Of-Band Envelope Reply activity instead of just calling everything that’s sent back after the initial mailserver connection a Soft Bounce.

Notably, most OoO/vacation/PTO messages don’t go back to the envelope MAIL FROM, so most aren’t seen by Marketo in the first place. The closest we have to a standard (though it’s only a recommendation, not a true standard) is RFC 3834. From 3834, it’s very clear that autoresponder messages should all go to the MAIL FROM! But in the real world, without a real standard to guide them, apps usually decide to send to the header From: (which is why they end up in users’ inboxes, not at Marketo).

[Darshil_Shah1]

Agreed - not a fan of mail delivered to inbox logging soft bounce with 550 error code later due to OOO / auto - replies too. It can be misleading for people who don't know about this prior upon seeing these soft bounces logged in the Marketo. Thank you for sharing this, Sandy!