SPF Record Syntax

Source: https://dmarcian.com/spf-syntax-table/

SPF Record Syntax

We have developed this comprehensive guide to increase your SPF understanding and help troubleshoot issues our application might have brought to your attention.  Having a valid and accurate SPF record will lead to improved authentication coverage, deliverability and help promote your desired level of security for your domains.

Don’t have a dmarcian account? You can still query the contents of your SPF record using our SPF Survey tool.

Create a free account now to have dmarcian monitor your SPF, DKIM and DMARC records for you automatically.  Get instant visibility into delivery errors, phishing and impersonation attempts with dmarcian’s SaaS Platform.

Use the navigation menu just below to jump to the particular element of your SPF record in question.  Additional information about SPF can be found in the linked articles at the bottom of this document.


Mechanisms can be used to describe the set of hosts which are designated outbound mailers for the domain and can be prefixed with one of four qualifiers:

+    (Pass)
–     (Fail)
~    (SoftFail)
?     (Neutral)

If a mechanism results in a hit, its qualifier value is used.  The default qualifier is “+“, i.e. “Pass”. Mechanisms are evaluated in order. If no mechanism or modifier matches, the default result is “Neutral”.

More in-depth information on the differences between “~” and “–” can be found here


“v=spf1 -all”

“v=spf1 a -all”

“v=spf1 a mx -all”

“v=spf1 +a +mx -all”

If a domain has no SPF record at all, the result is “None”. If a domain has a temporary error during DNS processing, you get the result “TempError” (called “error” in earlier drafts). If a syntax or evaluation error occurs (eg. the domain specifies an unrecognized mechanism) the result is “PermError” (formerly “unknown”).

Evaluation of an SPF record can return any of these results:

ResultExplanationIntended action
PassThe SPF record designates the host to be allowed to sendaccept
FailThe SPF record has designated the host as NOT being allowed to sendreject
SoftFailThe SPF record has designated the host as NOT being allowed to send but is in transitionaccept but mark
NeutralThe SPF record specifies explicitly that nothing can be said about validityaccept
NoneThe domain does not have an SPF record or the SPF record does not evaluate to a resultaccept
PermErrorA permanent error has occurred (eg. badly formatted SPF record)unspecified
TempErrorA transient error has occurredaccept or reject

The “all” mechanism


This mechanism always matches. It should always go at the end of the SPF record.


“v=spf1 mx ~all”
Allow domain’s MXs to send mail for the domain, prohibit all others.

“v=spf1 ~all”
The domain sends no mail at all.

“v=spf1 +all”
The domain allows all IP address on the internet to send mail.  Though ‘valid’, this is not recommended.

The “ip4” mechanism


The argument to the “ip4:” mechanism is an IPv4 network range. If no prefix-length is given, /32 is assumed (singling out an individual host address). Be careful to include a prefix-length greater than /16, as delivery to small smaller receivers may be impacted.


“v=spf1 ip4: ~all”
Allow any IP address between and

The “ip6” mechanism


The argument to the “ip6:” mechanism is an IPv6 network range. If no prefix-length is given, /128 is assumed (singling out an individual host address).


“v=spf1 ip6:1080::8:800:200C:417A/96 ~all”
Allow any IPv6 address between 1080::8:800:0000:0000 and 1080::8:800:FFFF:FFFF.

“v=spf1 ip6:1080::8:800: ~all”
Allow any IPv6 address between 1080::8:800:0000:0000 and 1080::8:800:FFFF:FFFF.

The “a” mechanism


All the A records for domain are tested. If the client IP is found among them, this mechanism matches. If the connection is made over IPv6, then an AAAA lookup is performed instead.

If domain is not specified, the current domain is used.

The A records have to match the client IP exactly, unless a prefix-length is provided, in which case each IP address returned by the A lookup will be expanded to its corresponding CIDR prefix, and the client IP will be sought within that subnet.


“v=spf1 a ~all”
The current domain is used.

“v=spf1 a:example.com ~all”
Equivalent if the current domain is example.com.

“v=spf1 a:mailers.example.com ~all”
Perhaps example.com has chosen to explicitly list all the outbound mailers in a special A record under mailers.example.com.

“v=spf1 a/24 a:offsite.example.com/24 ~all”
If example.com resolves to, the entire class C of would be searched for the client IP. Similarly for offsite.example.com. If more than one A record were returned, each one would be expanded to a CIDR subnet.

The “mx” mechanism


All the A records for all the MX records for domain are tested in order of MX priority. If the client IP is found among them, this mechanism matches.

If domain is not specified, the current domain is used.

The A records have to match the client IP exactly, unless a prefix-length is provided, in which case each IP address returned by the A lookup will be expanded to its corresponding CIDR prefix, and the client IP will be sought within that subnet.


“v=spf1 mx mx:deferrals.domain.com ~all”
Perhaps a domain sends mail through its MX servers plus another set of servers whose job is to retry mail for deferring domains.

“v=spf1 mx/24 mx:offsite.domain.com/24 ~all”
Perhaps a domain’s MX servers receive mail on one IP address, but send mail on a different but nearby IP address.

The “ptr” mechanism


The hostname or hostnames for the client IP are looked up using PTR queries. The hostnames are then validated: at least one of the A records for a PTR hostname must match the original client IP. Invalid hostnames are discarded. If a valid hostname ends in domain, this mechanism matches.

If domain is not specified, the current domain is used.

If possible, you should avoid using this mechanism in your SPF record, because it will result in a larger number of expensive DNS lookups.


“v=spf1 ptr ~all”
A domain which directly controls all its machines (unlike a dialup or broadband ISP) allows all its servers to send mail. For example, hotmail.com or paypal.com might do this.

“v=spf1 ptr:otherdomain.com ~all”
Any server whose hostname ends in otherdomain.com is designated.

The “exists” mechanism


Perform an A query on the provided domain. If a result is found, this constitutes a match. It doesn’t matter what the lookup result is – it could be

When you use macros with this mechanism, you can perform RBL-style reversed-IP lookups, or set up per-user exceptions.


In the following example, the client IP is and the current domain is example.com.

“v=spf1 exists:example.com ~all”

If example.com does not resolve, the result is fail. If it does resolve, this mechanism results in a match.

The “include” mechanism


The specified domain is searched for a match. If the lookup does not return a match or an error, processing proceeds to the next directive. Warning: If the domain does not have a valid SPF record, the result is a permanent error. Some mail receivers will reject based on a PermError.


In the following example, the client IP is and the current domain is example.com.

“v=spf1 include:example.com ~all”

If example.com has no SPF record, the result is PermError.
Suppose example.com’s SPF record were “v=spf1 a ~all”.
Look up the A record for example.com. If it matches, return Pass.
If there is no match, other than the included domain’s “~all”, the include as a whole fails to match; the eventual result is still Fail from the outer directive set in this example

Trust relationships — The “include:” mechanism is meant to cross administrative boundaries. Great care is needed to ensure that “include:” mechanisms do not place domains at risk for giving SPF Pass results to messages that result from cross user forgery. Unless technical mechanisms are in place at the specified other domain to prevent cross user forgery, “include:” mechanisms should give a Neutral rather than Pass result. This is done by adding “?” in front of “include:”.

The example would then be:

“v=spf1 ?include:example.com ~all”


Modifiers are optional. A modifier may appear only once per record. Unknown modifiers are ignored.

The “redirect” modifier


The SPF record for domain replaces the current record. The macro-expanded domain is also substituted for the current domain in those lookups.

If a ‘redirect’ modifier is used, the SPF record should not also include the ‘all’ mechanism.  If both are present, the ‘redirect’ modifier is ignored.  Any ‘redirect’ modifiers beyond the first will be ignored.


In the following example, the client IP is and the current domain is example.com.

“v=spf1 redirect=example.com”

If example.com has no SPF record, that is an error; the result is unknown.
Suppose example.com’s SPF record was “v=spf1 a ~all”.
Look up the A record for example.com. If it matches, return Pass.
If there is no match, the exec fails to match, and the ~all value is used.

The “exp” modifier


If an SMTP receiver rejects a message, it can include an explanation. An SPF publisher can specify the explanation string that senders see. This way, an ISP can direct nonconforming users to a web page that provides further instructions about how to configure SASL.

The domain is expanded; a TXT lookup is performed. The result of the TXT query is then macro-expanded and shown to the sender. Other macros can be used to provide a customized explanation.

The exp modifier may only contain printable ASCII characters.

Too many lookups?

Over the past decade, it has become increasingly easier to send email.  Countless Sources have entered the marketplace, each providing a specialized toolset tailored to address modern day needs of marketers, developers, and small businesses.  Along with this expansion, email authentication, specifically SPF, has become an increasingly complex matter to navigate.

Within the SPF RFC specification (essentially internet law) there lies a practical limit of how many “DNS-querying mechanisms” a single SPF record can contain. That limit is ten. The ten maximum lookup states that a domain administrator (that’s you!) will not require the likes of Gmail or other receivers to conduct more than ten consecutive DNS lookups to see if you authorize a particular IP address to send mail on your behalf.

As it has become somewhat commonplace for any single organization to authorize a large number of disparate netblocks (due to the outsourced nature of email infrastructure), there remains what seems like the constant and unnecessary encroachment on the ten maximum lookup.  This limit however remains entirely practical and should be observed to ensure timely delivery and favorable inbox rates.  Further, the solution to avoid the limit is squarely addressed by other mainstream email best practices, long encouraged by major inbound receivers such as Gmail and Yahoo.

The single most practical solution to avoid the ‘too many lookups’ issue is to make use of sub-domains.  As each discrete sub.domain is afforded its own ten lookup maximum, SPF is effectively boundless.  Example:  hello.com is permitted ten lookups + sub.hello.com is permitted ten lookups.  Plainly put, you should never run in to the ten maximum lookup condition if you are correctly segmenting different mail streams (eg. transactional, corporate, marketing, etc.) on to discrete name space.

In this sub section “delivery tips’ of the Gmail postmaster site, it is recommended to;

  • Use separate email addresses
  • Send mail from different domains and/or IP addresses

In summary, you should not run in to the 10 lookup maximum. If you do, we’ve outlined some additional strategies and knowledge-base materials on how to navigate.

Additional Reading:

– Video: How SPF works
– Additional reading on ‘too many lookups’
– Common misconceptions on SPF
– SPF Surveyor Tool
– What is the difference between SPF ~all and -all?

Online alati



IntoDNS checks the health and configuration and provides DNS report and mail servers report. And provides suggestions to fix and improve them, with references to protocols’ official documentation.


DNS records and worldwide DNS propagation checker

Do a quick DNS propagation lookup for any domain name and check DNS data collected from all location for confirming that the website is completely propagated or not worldwide.




This test will list MX records for a domain in priority order. The MX lookup is done directly against the domain’s authoritative name server, so changes to MX Records should show up instantly. You can click Diagnostics , which will connect to the mail server, verify reverse DNS records, perform a simple Open Relay check and measure response time performance. You may also check each MX record (IP Address) against 105 DNS based blacklists . (Commonly called RBLs, DNSBLs)

Microsoft Remote Connectivity Analyzer


Message Header Analyzer





SSL Online tools by Namecheap

SSL Server Test

This free online service performs a deep analysis of the configuration of any SSL web server on the public Internet. Please note that the information you submit here is used only to provide you the service. We don’t use the domain names or the test results, and we never will.

SSL/TLS Capabilities of Your Browser



Cisco Talos


IPVOID – Blacklist Check



Scan an IP address through multiple DNS-based blacklists (DNSBL) and IP reputation services, to facilitate the detection of IP addresses involved in malware incidents and spamming activities. This service checks in real-time an IP address through more than 80 IP reputation and DNSBL services. This service is built with the IP Reputation API by APIVoid.



IBM X-Force Exchange




Barracuda central


Symantec IP Reputation Investigation


IP Reputation with IPQualityScore


VirusTotal URL and IP search


IP Analyzer





Have I Been Pwned?


Dashlane-sponsored How Secure Is My Password?


Koje su stvarne brzine GPRS, EDGE, UMTS, HSPA..?


  • GSM (Global System for Mobile Communications) 2G – 9.6Kbps
  • GPRS (General packet radio services) 2.5G – 35Kbps do 171kbps


  • EDGE (Enhanced Data rates for GSM Evolution) 2.75G – 120Kbps do 384Kbps
  • UMTS (Universal Mobile Telecommunications System) 3G — 384Kbps do 2Mbps
  • HSPA (software upgrade to UMTS, teoretski čak 42Mbps) 3.5G – 600Kbps do 10Mbps, u prosjeku 1~3Mbps


  • WiMAX/LTE “4G” (U teoriji 100Mbps) — 3Mbps do 10Mbps prosječno, 20Mbps+ vršna download brzina

Imena dijakritičkih znakova na engleskom jeziku

~ tilde (rhymes with Hilda)
! exclamation mark
@ I just know it as the ‘at’ symbol
# hash
$ dollar (don’t tell me you didn’t know that one. ;-D )
% per cent
^ caret (I think that’s the correct spelling and I think it’s pronounced cah (as in cat) and then ray so cah-ray)
& ampersand
* asterisk
( left bracket
) right bracket
_ underscore
– hyphen
= equals
+ plus (bet you had to go to school to learn the last two – lol)
{ left parenthesis
} right parenthesis (these are also called “curly brackets”)
[ forgotten
] also forgotten but it’s the right one! I think they are just known as square brackets but do have a proper name.
| pipe – the picture on the key looks like two lines, one above the other.
\ backslash
: colon
; semi-colon
” inverted comma
‘ apostrophe
< left angled bracket or left chevron
> right angled bracket or right chevron
, comma
. fullstop
? question mark
/ slash

Izvor: http://answers.yahoo.com/question/index?qid=20080930224101AAEtpav

Testiram te preko one stvari RegEx

Pita Mujo Hasu koji je datum, a ovaj mudro šuti.
Pita ponovo Mujo Hasu: Znaš li barem koliko je sati?
Odgovara Mujo: Ne znam ali je sigurno nešto u ovom obliku (\d{4}-\d{2}-\d{2}\s+\d{2}:\d{2}:\d{2})

Evo nekih dobrih linkova oko RegEx-a

TeamViewer Daemon is not running

Nakon instalacije TeamViewera 8 na openSuSE12.2 64bit  sve radi normalno. Možemo se spajati, paliti/gasiti aplikaciju i opet uspješno se spojiti prijatelju na ra?unalo.  Nakon restarta ra?unala TeamViewer nam otkazuje poslušnost i javlja poruku TeamViewer Daemon is not running, Please start teamviewerd and then restart TeamViewer.

Potrebno je pokrenuti donju komandu u terminalu i ponovno pokrenuti TeamViewer


Unos VMware Workstation licence kroz terminal

Unos nove VMware Workstation licence kroz GUI (Help>Enter Licence Key…) u verziji 9.0.x na openSuSE12.2 na mojem ra?unalu iz nekog razloga jednostavno nije mogu?e napraviti. Obzirom da nije upisana validna licenca nemogu se upaliti virtualne mašine. Dolje se nalazi komanda kojom se kroz terminal upisuje licenca u Workstation.

/usr/lib/vmware/bin/vmware-vmx-debug –new-sn XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

Umjesto XXXXX-XXXXX-XXXXX-XXXXX-XXXXX stavite svoju licencu.

Izvor: https://wiki.archlinux.org/index.php/VMware

Metapixel – Izrada mozaika

Komanda za kreiranje umanjenih slika (tiles) koje ?e služiti za izradu mozaika po uzoru na original sliku:

metapixel-prepare -r /home/korisnik/putanja/do/slika/za/mozaik/ male_slike –width=64 –height=64

Korišteni switchevi:

  • -r metapixel-prepare prolazi rekurzivno kroz podirektorije /home/korisnik/putanja/do/slika/za/mozaik/
  • “male_slike” je direktorij u koji ?e se smjestiti sve umanjene slike tokom ove pripreme. Mapa se ne kreira automatski i mora postojati unaprijed pripremljena.
  • –width= i –height= su dimenzije umanjenih slika (tiles). Optimalno bi bilo da ne budu ve?e od 128×128 piksela.

Napomena: Metapixel prepoznaje samo JPEG, PNG i GIF datoteke.

Primjer komande za generiranje mozaika:

metapixel –library male_slike –metapixel mozaik_master.jpg mozaik001_scale1.jpg -s 1
metapixel –library male_slike –collage mozaik_master.jpg mozaik001_scale2.jpg -s 2

Korišteni switchevi:

  • –library male_slike ovdje odabiremo direktodij gdje u pohranjene umanjene slike
  • –metapixel ili –collage služe za generiranje mozaika ili kolaža, osobno preferiram switch metapixel jer mi on generira mozaik
  • mozaik_master.jpg je ime originalne slike na temelju koje želimo napraviti mozaik u datoteku npr. mozaik001_scale2.jpg
  • -s 2 je primjer za pove?avanje mozaika u skali 2:1 u odnosu na originalnu sliku


  • http://www.complang.tuwien.ac.at/schani/metapixel/
  • http://blogs.pcworld.co.nz/pcworld/tux-love/2009/09/metapixel_magic.html
  • http://doc.ubuntu-fr.org/metapixel

Popravak oštećene Outlook PST datoteke

Popravak oštećene pst datoteke se može napraviti sa ugrađenim alatom Inbox Repair Tool (scanpst.exe). Obzirom da svaka verzija office ima drugačije putanje do scanpst.exe dolje se nalazi za svaku verziju točno mjesto tog alata.

Outlook 2013

32-bit Windows C:\Program Files\Microsoft Office\Office15
64-bit Windows C:\Program Files (x86)\Microsoft Office\Office15
64-bit Outlook C:\Program Files\Microsoft Office\Office15
Click-to-Run C:\Program Files\Microsoft Office 15\root\office15

Outlook 2010

32-bit Windows C:\Program Files\Microsoft Office\Office14
64-bit Windows C:\Program Files (x86)\Microsoft Office\Office14
64-bit Outlook C:\Program Files\Microsoft Office\Office14

Outlook 2007

32-bit Windows C:\Program Files\Microsoft Office\Office12
64-bit Windows C:\Program Files (x86)\Microsoft Office\Office12

Outlook 2003

32-bit Windows C:\Program Files\Common Files\System\MSMAPI\<locale ID>
64-bit Windows C:\Program Files (x86)\Common Files\System\MSMAPI\<locale ID>

Outlook 2002/XP

C:\Program Files\Common Files\System\MAPI\<locale ID>\scanpst.exe

Outlook 2000

C:\Program Files\Common Files\System\MAPI\<locale ID>\NT\scanpst.exe

Outlook 97 / Outlook 98

C:\Program Files\Common Files\Windows Messaging\scanpst.exe


Izvor: http://www.msoutlook.info/question/77



Dodatni alati za oporavak Outlooka

OutlookTools http://www.howto-outlook.com/products/outlooktools.htm