Real-time email delivery metrics across major providers
Last updated: Sep 30, 2026 8:15 AM PDT
Current ESP Status
| Provider | P95 Latency (s) | Retry Rate | Trend | Status | Details |
|---|---|---|---|---|---|
| Apple iCloud | 2.54 | 1.6% | ▬ | Healthy | View Details |
| Comcast / Xfinity | 5.99 | 3.5% | ▲ | Issues | View Details |
| GMX / WEB.de | 1.83 | 0.0% | ▬ | Healthy | View Details |
| Google Mail | 0.89 | 0.4% | ▲ | Healthy | View Details |
| Microsoft 365 | 1.64 | 0.2% | ▬ | Healthy | View Details |
| Outlook / Hotmail | 1.61 | 0.1% | ▬ | Healthy | View Details |
| Spectrum / Charter | 1.36 | 0.0% | ▬ | Healthy | View Details |
| Yahoo / AOL | 0.86 | 4.6% | ▲ | Healthy | View Details |
Details for Apple iCloud
← Back to OverviewP95 Latency (24 hours)
Delivery Issues (24 hours)
Retry and Bounce RatesTop Delivery Failure Reasons (24 hours)
| Reason | Distribution |
|---|---|
| Apple CS01 policy rejection |
74.4%
|
| Mailbox over quota |
9.9%
|
| Temporary resource unavailable |
9.1%
|
| Unknown |
3.3%
|
| Apple HM08 policy rejection |
1.7%
|
| Invalid address (user doesn't exist) |
1.2%
|
| Network error (timeout/refused/reset) |
0.4%
|
About this data
- The numbers on this page come from SMTP telemetry that Groups.io collects each day.
- Latency measures the time from the start of the connection until we receive the server's response to the DATA command.
- Metrics are updated every five minutes and down-sampled into 5-minute buckets; raw data older than seven days is automatically purged, and roll-ups are kept for 90 days.
Need deeper, real-time insight?
- Query ANY domain - not just the majors you see above
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