Summary
Claude.ai sign-in (magic link) emails have become progressively slower to arrive since early July 2026, and for the past week every one takes 2–5 minutes instead of seconds. This affects logging in to claude.ai, which in turn delays getting into Claude Code when a session expires. Filing here for visibility in case others are seeing the same; already reported to product support via the support.claude.com messenger (conversation ID 215475262239306).
Environment
- Recipient: a Microsoft 365 / Exchange Online mailbox (details shared in the support conversation)
- MX points directly to
*.mail.protection.outlook.com, no third-party mail filter
- Sender:
[email protected] via SendGrid (message-ids ...@geopod-ismtpd-*)
Measurements
Delay = time between the email's Date header (set at send time; it matches the request timestamp Anthropic embeds in the subject line to the second) and delivery into the mailbox:
| Period |
Sign-in email delay |
| June 2026 |
3–11 s |
| Early July |
~60–100 s |
| Mid July |
up to ~216 s |
| Jul 20–28 (every message) |
99–317 s, avg ~207 s |
Example: message-id <vMrGW_hCTZC0Ci3c1LkLSA@geopod-ismtpd-20> — sent 2026-07-28 02:27:11 UTC, delivered 02:30:22 UTC (191 s).
Receiver side ruled out
During the same Jul 20–28 window, into the same mailbox:
- All other external senders delivered in 3–20 s (Amazon, Zoom, banks, e-sign vendors, etc.)
- Including at least one other SendGrid-originated sender (Zoom) at 5 s
So this doesn't look like Microsoft 365 throttling or SendGrid-wide; it appears isolated to the mail.anthropic.com sending stream, consistent with queuing in the magic-link sending pipeline.
Impact
Magic links are the only way into the account, so every login stalls for minutes; users request duplicate links, adding confusion about which one is valid.
Summary
Claude.ai sign-in (magic link) emails have become progressively slower to arrive since early July 2026, and for the past week every one takes 2–5 minutes instead of seconds. This affects logging in to claude.ai, which in turn delays getting into Claude Code when a session expires. Filing here for visibility in case others are seeing the same; already reported to product support via the support.claude.com messenger (conversation ID 215475262239306).
Environment
*.mail.protection.outlook.com, no third-party mail filter[email protected]via SendGrid (message-ids...@geopod-ismtpd-*)Measurements
Delay = time between the email's Date header (set at send time; it matches the request timestamp Anthropic embeds in the subject line to the second) and delivery into the mailbox:
Example: message-id
<vMrGW_hCTZC0Ci3c1LkLSA@geopod-ismtpd-20>— sent 2026-07-28 02:27:11 UTC, delivered 02:30:22 UTC (191 s).Receiver side ruled out
During the same Jul 20–28 window, into the same mailbox:
So this doesn't look like Microsoft 365 throttling or SendGrid-wide; it appears isolated to the
mail.anthropic.comsending stream, consistent with queuing in the magic-link sending pipeline.Impact
Magic links are the only way into the account, so every login stalls for minutes; users request duplicate links, adding confusion about which one is valid.