550 5.7.26: SPF hard fail
Gmail rejected the message because the sending IP is not allowed by the SPF record of the envelope domain, and that record ends in -all.
- Gmail
- Provider
- Permanent (5xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 550 5.7.26
- Provider
- Gmail and Google Workspace
- Temporary or permanent
- PermanentRefused for good: the message comes back to the sender, and resending it gets the same answer.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
550 5.7.26 …has an SPF record with a hard fail policy (-all)…
What it means
The envelope sender (MAIL FROM) domain publishes an SPF record ending in -all, which tells receivers to refuse mail from any server it does not list. The IP that delivered this message is not listed, so SPF failed hard and Gmail blocked the message, as Google says, to protect its users from spam and phishing. The bounce names the domain and the IP. Either that IP is a legitimate server missing from the record, or someone else is using your domain in the envelope. Forwarded mail can hit this too, because the forwarder's IP is not in the original sender's record.
Common causes
- A new sending service or server that was never added to the SPF record.
- Mail forwarded through a server that the original domain's SPF does not list.
- Someone spoofing your domain in the envelope sender.
How to fix it
- 01Check the IP in the bounce against your SPF record with an SPF lookup.
- 02If it is one of your senders, add it, or its include, to the record.
- 03If it is not yours, leave the record as it is: the rejection is protecting your domain.
- 04For forwarding, ask the forwarder to rewrite the envelope sender (SRS), and sign with DKIM, which survives forwarding.
Sources
What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.
- Gmail SMTP errors and codes (Google Workspace Admin Help)knowledge.workspace.google.com
Related codes
- 550 5.7.26Unauthenticated sender, blocked.Gmail rejected the message because it passed neither SPF nor DKIM, and Gmail requires every sender to pass at least one.
- 550 5.7.27SPF did not pass, blocked.Gmail rejected the message because it failed SPF, which Gmail requires of bulk senders along with DKIM.
- 550Mailbox unavailable.The receiving server permanently refused the message for this recipient: the mailbox does not exist, cannot be reached, or the server rejected the message by policy.
- 550 5.7.26Multiple authentication checks failed.The message failed more than one authentication check, for example SPF and DKIM, and the receiving server's policy rejects it.
Further reading
All 108 Gmail codesEvery code in the wikiPaste your own bounce