This is the last check in the series, and it's an important one. Most Zoho environments don't exist in isolation, they're connected to email providers, calendars, telephony systems, e-commerce platforms, and countless other tools via integrations. When something goes wrong, it can genuinely look like a Zoho fault when the real cause is sitting on the other side of one of those connections.

Why integrations muddy the water

An integration connects Zoho to an external system, so data or triggers can flow in either direction automatically. If the issue you're seeing happens specifically when that integration is involved, for example a record not syncing, an email not sending, or a webhook not firing, the fault may well sit with the third-party platform, its own outages, its API limits, or a recent change it made on its end, rather than with Zoho.

How to narrow it down

1. Reproduce the issue without the integration. If you can carry out the same action manually inside Zoho, without the third-party system involved, and it works fine, that points strongly towards the integration itself.
2. Check the other platform's own status page. Most major services (Shopify, Microsoft 365, Google Workspace, and so on) publish their own live status pages, much like Zoho does.
3. Look for recent changes. Was a password recently reset, an API key regenerated, a permission changed, or an app update rolled out on the third-party side? Any of these can silently break a previously working connection.
4. Check for rate limits or quotas. Many external platforms cap how many requests they'll accept in a given period. If a sync has been running fine for months and suddenly starts failing intermittently, an exceeded limit is a common culprit.

That's the end of this series

If you've worked through these checks and you're still no closer to an answer, that's exactly the point at which it's worth bringing in a second pair of eyes.