[1] Sender Policy Framework - Wikipedia (2009-09-27 09:05:23 +09:00 版) http://ja.wikipedia.org/wiki/Sender_Policy_Framework

[6] RFC 4408: Sender Policy Framework (SPF) for Authorizing Use of Domains in E-Mail, Version 1, 2023-12-02T08:31:40.000Z, 2023-12-02T08:51:42.704Z https://www.rfc-editor.org/rfc/rfc4408.html

[10] RFC Errata Report » RFC Editor, 2023-12-02T08:54:57.000Z https://www.rfc-editor.org/errata/rfc4408

[2] RFC 6577 - Authentication-Results Registration Update for Sender Policy Framework (SPF) Results ( (2012-07-02 02:43:00 +09:00 版)) http://tools.ietf.org/html/rfc6577

[3] RFC 6652 - Sender Policy Framework (SPF) Authentication Failure Reporting Using the Abuse Reporting Format ( (2012-08-16 05:09:52 +09:00 版)) http://tools.ietf.org/html/rfc6652

[4] RFC 6686 - Resolution of the Sender Policy Framework (SPF) and Sender ID Experiments ( (2012-07-21 03:14:53 +09:00 版)) http://tools.ietf.org/html/rfc6686

[5] Fix "CharacterStringTooLong" Errors When Creating TXT Records (2019-01-10 12:49:21 +09:00) https://aws.amazon.com/jp/premiumsupport/knowledge-center/characterstringtoolong-error/

[7] RFC 4406: Sender ID: Authenticating E-Mail, 2023-12-02T08:31:42.000Z, 2023-12-02T08:54:17.765Z https://www.rfc-editor.org/rfc/rfc4406.html

[8] RFC 4407: Purported Responsible Address in E-Mail Messages, 2023-12-02T08:31:41.000Z, 2023-12-02T08:54:32.151Z https://www.rfc-editor.org/rfc/rfc4407.html

[9] RFC Errata Report » RFC Editor, 2023-12-02T08:54:41.000Z https://www.rfc-editor.org/errata/rfc4407

[11] RFC 4405: SMTP Service Extension for Indicating the Responsible Submitter of an E-Mail Message, 2023-12-02T08:55:42.000Z, 2023-12-02T08:56:05.931Z https://www.rfc-editor.org/rfc/rfc4405.html

[12] SPF レコードを定義する: 基本設定 - Google Workspace 管理者 ヘルプ, 2024-03-21T08:09:56.000Z https://support.google.com/a/answer/10685031?hl=ja