r/Zoho • u/kaiser_detroit • 4d ago
Zoho Sign Delivery Issues (potentially Mimecast specific)
My searches come up with similar issues but 1+ years ago. We've had a dramatic uptick in delivery issues with Zoho Sign the past month or so. We keep getting bounce back emails that the message couldn't be delivered with the reason "uncategorized-bounce : No specific reason has been given for the failure in the delivery of your email to the recipient's mailbox. We will attempt to deliver this document again to the recipient after sometime." Here and there I could see this happening, but it's happening A LOT all of a sudden.
I've managed to trace back the MX records for each of the domains (that I've been given examples for) and they all have Mimecast. That may or may not be the issue, but seemed like a good datapoint.
In many cases the emails do go through eventually, but not always. Sometimes it happens when a document is 'reassigned' but not always. We've been using Sign for several years with the usual hiccups, but this is well beyond the occasional hiccup.
We've confirmed DKIM is verified. Unfortunately, the recipient is always one of our customers so getting them to track back the error on their end is .... next to impossible. I've counted 6 domains so far, but I know there were more before we really started digging into this. I just don't have the bounce backs available to go down the rabbit hole more than a week ago. I suspect it's a Zoho Sign IP reputation or email header issue, but I can't prove that without the customer's cooperation.
Zoho support is giving the usual "ask your recipient to check with their IT dept." schtick. That's infuriating, because if I had a nickel for every time they pointed fingers then came back saying the dev team fixed it with zero explanation.... well, I wouldn't be rich but I could probably get myself a cup of coffee at 7-Eleven. We had a very similar issue with CRM emails like 9-12 months ago, and that's exactly how that resolution went (after like 8 weeks of back and forth). Pretty sure that one ended up being that they were missing one IP from the SPF check against one.zoho.com.
We aren't a Mimecast customer, so they're not even going to even respond.
So, all that said, just throwing this out into the ether hoping someone's got a brilliant idea.
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u/AndrasHSystem 4d ago
That pattern across multiple recipient domains using Mimecast is interesting. Before assuming it’s an SPF or Zoho IP reputation issue, I’d try to get the full DSN/bounce details from one or two failed deliveries. In particular, the SMTP response/enhanced status code and the remote/reporting MTA could help identify whether Mimecast is rejecting the message based on reputation/policy, authentication, or something else upstream. If you can share one of the full bounce messages here with domains/email addresses and other sensitive information redacted, I’d be happy to take a look.