Sudden drop in deliverability - bot filter to blame?

[anissabrach]

Hi,

I recently switched on the bot filters and we have seen a huge drop in deliverability down from 90%+ to more like 40%.

I wonder if it's some how related?

Contacts that previously received and opened emails are now marked as soft bounced with reason that their inbox is full. And these are our customers, so we know that they should receive the communication.

One thing to note is that we had to upload customer lists due to some sync restrictions with SFDC. This may also be an issue for deliverability.

Anyone else seen this? Any other ideas?

[Darshil_Shah1]

Well, IMHO this seems to be a disconnected issue from the bot filtering as the latter tries filtering (or logging separately) opens/clicks from the email scanners (aka bots) in the activity log, i.e., engagements after the email has been delivered to the recipients. Whereas, the mailbox full error, as the name suggests, indicates that the recipient's MX server has rejected the email because their mailbox was full when Marketo attempted to deliver the email.

Sending emails to purchased lists (i.e., to people who never opted-in to get emails from you) can affect deliverability, but that doesn't seem to be the case here, as you're sending emails to your customers who earlier were able to receive emails from you. Would love to hear thoughts from other community members on this as well.

[SanfordWhiteman · Accepted solution]

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I recently switched on the bot filters and we have seen a huge drop in deliverability down from 90%+ to more like 40%.

I wonder if it's some how related?

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No. The bot filter acts as a filter within Marketo on Activity Logs. It has no relationship to the the email being delivered or not.

The Mailbox Full SMTP-level error may be deliberately misleading. That is, an SMTP server can return any error it wants if it finds your email objectionable, it doesn’t have to be the “real” reason. But I would be 100% sure this is not related to bot detection. Rather, it’s due to sending to bad addresses (you might have some typo that was loaded in bulk) or to be being blocked by the recipient. Purchasing lists is of course a good way to be blocked (and is a violation of Marketo TOS).

[anissabrach]

So interestingly, I switched the bot activities off and deliverability went back up. Not to what we used to see but pretty much doubled. This seems super odd, as I also understood that it should really only affect opens/close reporting.

How would that have an impact?

[Christiane_Rode]

What are you using to measure deliverability? One thing I would check is that you're not accidentally filtering data that should be included.

Another thing to consider, too, is the timing of when you turned activity filtering on and off. There's a variable there that you'll also want to consider. Is it possible that the timeframe when activity filtering was on was during a period when people may have been out of the office or when their inboxes were full, and then when you turned the filtering off, people had cleared out their inboxes, and some of these soft-bounce issues resolved themselves? 

I'd also check your authentication settings (SPF, DKIM). Were there any changes made on your end during one of these timeframes that just happened to coincide with toggling filtering on and off?

There are other variables to consider, too, since this wasn't a testing scenario. But, as others have mentioned, deliverability shouldn't be affected by this.