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Regular Expression Details

Title	Test Find SPF checker
Expression	^v=spf1[ \t]+[+?~-]?(?:(?:all)\|(?:ip4(?:[:][0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})?(?:/[0-9]{1,2})?)\|(?:ip6(?:[:]([0-9A-Fa-f]{1,4}:){7}[0-9A-Fa-f]{1,4})?(?:/[0-9]{1,2})?)\|(?:a(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+)?(?:/[0-9]{1,2})?)\|(?:mx(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+)?(?:/[0-9]{1,2})?)\|(?:ptr(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+))\|(?:exists(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+))\|(?:include(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+))\|(?:redirect(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+))\|(?:exp(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+))\|)(?:(?:[ \t]+[+?~-]?(?:(?:all)\|(?:ip4(?:[:][0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})?(?:/[0-9]{1,2})?)\|(?:ip6(?:[:]([0-9A-Fa-f]{1,4}:){7}[0-9A-Fa-f]{1,4})?(?:/[0-9]{1,2})?)\|(?:a(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+)?(?:/[0-9]{1,2})?)\|(?:mx(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+)?(?:/[0-9]{1,2})?)\|(?:ptr(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+))\|(?:exists(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+))\|(?:include(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+))\|(?:redirect(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+))\|(?:exp(?:[:][A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-][A-Za-z0-9])?)+))\|))*)?$
Description	I use "preg_match" function on PHP with this expression. Detects a valid SPF expression. Warnings: ip6 register only works in "no compressed" form. "trim" the string before use the expression (or add [ \t]+ after ^ and before $)
Matches	v=spf1 +a +mx -all \| v=spf1 +a +mx +ip4:192.168.0.0/24 +ptr:mydomain.com -all \| v=spf1 include:spf.alternative.com
Non-Matches	v=spf1 \| v=spf2 -all \| v=spf1 *all
Author	Rating: Oscar Martín
Source
Your Rating	Bad 1 2 3 4 5 Good

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Existing User Comments

Title: version 1.1
Name: Fabian
Date: 2/9/2017 4:46:37 PM
Comment:
Hi, I did have some issues with _ in domain names, ip6 and redirect= I did make some minor adjustments: ^v=spf1[ \t]+[+?~-]?(?:(?:all)|(?:ip4(?:[:][0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})?(?:/[0-9]{1,2})?)|(?:ip6(?:[:]([0-9A-Fa-f]{1,4}:){1,7}[:0-9A-Fa-f]{1,4})?(?:/[0-9]{1,2})?)|(?:a(?:[:][\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+)?(?:/[0-9]{1,2})?)|(?:mx(?:[:][\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+)?(?:/[0-9]{1,2})?)|(?:ptr(?:[:][\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+))|(?:exists(?:[:][_A-Za-z0-9](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+))|(?:include(?:[:][_A-Za-z0-9](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+))|(?:redirect([=:]{1}[\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+))|(?:exp(?:[:][\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+))|)(?:(?:[ \t]+[+?~-]?(?:(?:all)|(?:ip4(?:[:][0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})?(?:/[0-9]{1,2})?)|(?:ip6(?:[:]([0-9A-Fa-f]{1,4}:){1,7}[:0-9A-Fa-f]{1,4})?(?:/[0-9]{1,2})?)|(?:a(?:[:][\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+)?(?:/[0-9]{1,2})?)|(?:mx(?:[:][\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+)?(?:/[0-9]{1,2})?)|(?:ptr(?:[:][\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+))|(?:exists(?:[:][\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+))|(?:include(?:[:][\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+))|(?:redirect([=:]{1}[\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+))|(?:exp(?:[:][\w-](?:[\w-]*[\w-])?(?:\.[\w-](?:[\w-]*[\w-])?)+))|))*)?$

Title: Slight modification
Name: Marcus
Date: 5/14/2014 10:00:08 AM
Comment:
Does not work for ptr without explicitly specified domain. This modification extends the regex respectively ^v=spf1[ \t]+[+?~-]?(?:(?:all)|(?:ip4(?:[:][0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]\ {1,3})?(?:/[0-9]{1,2})?)|(?:ip6(?:[:]([0-9A-Fa-f]{1,4}:){7}[0-9A-Fa-f]{1,4})?(?:/[0-9]{1,2})?)|(?:a(?:[:][A-Z\ a-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+)?(?:/[0-9]{1,2})?)|(?:mx(\ ?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+)?(?:/[0-9]{1,2})\ ?)|(?:ptr(?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+)?)|(?:\ exists(?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+))|(?:incl\ ude(?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+))|(?:redirec\ t(?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+))|(?:exp(?:[:]\ [A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+))|)(?:(?:[ \t]+[+?~-]\ ?(?:(?:all)|(?:ip4(?:[:][0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})?(?:/[0-9]{1,2})?)|(?:ip6(?:[:]([0-9A-\ Fa-f]{1,4}:){7}[0-9A-Fa-f]{1,4})?(?:/[0-9]{1,2})?)|(?:a(?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?(?:\.[A-\ Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+)?(?:/[0-9]{1,2})?)|(?:mx(?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])\ ?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+)?(?:/[0-9]{1,2})?)|(?:ptr(?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A\ -Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+)?)|(?:exists(?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za\ -z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+))|(?:include(?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0\ -9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+))|(?:redirect(?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9\ ])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?)+))|(?:exp(?:[:][A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?(?:\\ .[A-Za-z0-

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