Mars two moons, Phobos and Deimos, are like the bay leaves of the solar system theyre fine I guess but what are they trying to do The larger satellite, Phobos.L4uB6PHdnY/hqdefault.jpg' alt='Mta Sa 1 3 3 Exercise' title='Mta Sa 1 3 3 Exercise' />SPF RFC 4.There is a list of errata that will get sent to the IETF after it has been fully reviewed.See other formats and historic editions of this document.Sender Policy Framework SPF for Authorizing Use of Domains in E Mail, Version 1.Status of This Memo.This memo defines an Experimental Protocol for the Internet community.It does not specify an Internet standard of any kind.Discussion and suggestions for improvement are requested.Distribution of this memo is unlimited.Copyright Notice.Copyright The Internet Society 2.Abstract. E mail on the Internet can be forged in a number of ways.In particular, existing protocols place no restriction on what a sending host can use as the reverse path of a message or the domain given on the SMTP HELOEHLO commands.This document describes version 1 of the Sender Policy Framework SPF protocol, whereby a domain may explicitly authorize the hosts that are allowed to use its domain name, and a receiving host may check such authorization.IESG Note. The following documents RFC 4.RFC 4. 40. 6, RFC 4.RFC 4. 40. 8 are published simultaneously as Experimental RFCs, although there is no general technical consensus and efforts to reconcile the two approaches have failed.As such, these documents have not received full IETF review and are published AS IS to document the different approaches as they were considered in the MARID working group.The IESG takes no position about which approach is to be preferred and cautions the reader that there are serious open issues for each approach and concerns about using them in tandem.The IESG believes that documenting the different approaches does less harm than not documenting them.Note that the Sender ID experiment may use DNS records that may have been created for the current SPF experiment or earlier versions in this set of experiments.Depending on the content of the record, this may mean that Sender ID heuristics would be applied incorrectly to a message.Depending on the actions associated by the recipient with those heuristics, the message may not be delivered or may be discarded on receipt.Participants relying on Sender ID experiment DNS records are warned that they may lose valid messages in this set of circumstances.Participants publishing SPF experiment DNS records should consider the advice given in section 3.RFC 4. 40. 6 and may wish to publish both vspf.Participants in the Sender ID experiment need to be aware that the way Resent header fields are used will result in failure to receive legitimate email when interacting with standards compliant systems specifically automatic forwarders which comply with the standards by not adding Resent headers, and systems which comply with RFC 8.RFC 2. 82. 2 Resent semantics.It would be inappropriate to advance Sender ID on the standards track without resolving this interoperability problem.The community is invited to observe the success or failure of the two approaches during the two years following publication, in order that a community consensus can be reached in the future.Table of Contents 1.Introduction. The current E Mail infrastructure has the property that any host injecting mail into the mail system can identify itself as any domain name it wants.Hosts can do this at a variety of levels in particular, the session, the envelope, and the mail headers.Although this feature is desirable in some circumstances, it is a major obstacle to reducing Unsolicited Bulk E Mail UBE, aka spam.Furthermore, many domain name holders are understandably concerned about the ease with which other entities may make use of their domain names, often with malicious intent.This document defines a protocol by which domain owners may authorize hosts to use their domain name in the MAIL FROM or HELO identity.Compliant domain holders publish Sender Policy Framework SPF records specifying which hosts are permitted to use their names, and compliant mail receivers use the published SPF records to test the authorization of sending Mail Transfer Agents MTAs using a given HELO or MAIL FROM identity during a mail transaction.An additional benefit to mail receivers is that after the use of an identity is verified, local policy decisions about the mail can be made based on the senders domain, rather than the hosts IP address.This is advantageous because reputation of domain names is likely to be more accurate than reputation of host IP addresses.Furthermore, if a claimed identity fails verification, local policy can take stronger action against such E Mail, such as rejecting it.Protocol Status. SPF has been in development since the summer of 2.December 2. 00. 3.The design of SPF slowly evolved until the spring of 2.There have been quite a number of forms of SPF, some written up as documents, some submitted as Internet Drafts, and many discussed and debated in development forums.The goal of this document is to clearly document the protocol defined by earlier draft specifications of SPF as used in existing implementations.This conception of SPF is sometimes called SPF Classic.It is understood that particular implementations and deployments may differ from, and build upon, this work.It is hoped that we have nonetheless captured the common understanding of SPF version 1.Terminology. The key words MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL in this document are to be interpreted as described in RFC 2.This document is concerned with the portion of a mail message commonly called envelope sender, return path, reverse path, bounce address, 2.FROM, or MAIL FROM.Since these terms are either not well defined or often used casually, this document defines the MAIL FROM identity in Section 2.Note that other terms that may superficially look like the common terms, such as reverse path, are used only with the defined meanings from normative documents.Operation 2. 1. The HELO Identity.The HELO identity derives from either the SMTP HELO or EHLO command see RFC 2.These commands supply the SMTP client sending host for the SMTP session.Note that requirements for the domain presented in the EHLO or HELO command are not always clear to the sending party, and SPF clients must be prepared for the HELO identity to be malformed or an IP address literal.At the time of this writing, many legitimate E Mails are delivered with invalid HELO domains.It is RECOMMENDED that SPF clients not only check the MAIL FROM identity, but also separately check the HELO identity by applying the checkhost function Section 4 to the HELO identity as the lt sender.The MAIL FROM Identity.The MAIL FROM identity derives from the SMTP MAIL command see RFC 2.This command supplies the reverse path for a message, which generally consists of the sender mailbox, and is the mailbox to which notification messages are to be sent if there are problems delivering the message.RFC 2. 82. 1 allows the reverse path to be null see Section 4.RFC 2. 82. 1. In this case, there is no explicit sender mailbox, and such a message can be assumed to be a notification message from the mail system itself.When the reverse path is null, this document defines the MAIL FROM identity to be the mailbox composed of the localpart postmaster and the HELO identity which may or may not have been checked separately before.SPF clients MUST check the MAIL FROM identity.SPF clients check the MAIL FROM identity by applying the checkhost function to the MAIL FROM identity as the lt sender.Publishing Authorization.An SPF compliant domain MUST publish a valid SPF record as described in Section 3.This record authorizes the use of the domain name in the HELO and MAIL FROM identities by the MTAs it specifies.If domain owners choose to publish SPF records, it is RECOMMENDED that they end in all, or redirect to other records that do, so that a definitive determination of authorization can be made.Domain holders may publish SPF records that explicitly authorize no hosts if mail should never originate using that domain.When changing SPF records, care must be taken to ensure that there is a transition period so that the old policy remains valid until all legitimate E Mail has been checked.Checking Authorization.A mail receiver can perform a set of SPF checks for each mail message it receives.How to Deal With Constant, Nightmarish Subway Delays.Even if you dont live in New York, youve surely heard us complaining by now about the dramatic downward spiral of the nations largest mass transit system under the neglectful reign of Governor Andrew Cuomo.Besides leading to lost wages, chaotic after school pick ups, and missed medical appointments, the colossal systemwide breakdown of the MTA has also forced the citys mass transit riders to approach the commute more strategically.Below, tried and true tactics to arm yourself for the daily battle against an unwieldy and unreliable daily slog Use the Bathroom Ahead of Time.Self explanatory.You never know when a 2.Stay Updated With Transit Apps and Twitter Beefs.Besides checking the MTAs website for current service status, its smart to supplement with additional information from apps like Kickmap, which will show delays, and works offline, or the citys Transit app, which shows your best route options and upcoming train arrival times in addition to information on delays.As a rule, though, the real dirt can be found on Twitter.The NYCT Subway Twitter feed stays reasonably up to date, but the pro move is to dive into their mentions to see what other riders are saying about delays on your line The same advice follows for simply searching Twitter for your line of choice to see if anyone has pertinent news about the train youre about to take Leave Extremely Early.Extremely Late. For the day to day commute, most people we know now leave 1.You could also swing to the other end of the spectrum and leave late enough to avoid rush hour, if you have hours and a work schedule flexible enough to allow for it.Must be nice Doesnt mean your train wont get stuck indefinitely, but it does mean that you wont be crammed in with quite as many people when it happens.Pack Water and Snacks.Though eating on the subway is a controversial topicand food may soon become contrabandits arguably a safety precaution to at least bring water with you, and ideally, small snacks like nuts or granola bars as well.Getting stuck without light or air so long that people might get dehydrated or start to faint is not outside the realm of possibilityNote this doesnt mean its acceptable to break the no cooked food on the subway rule.It isnt. Bring Extra Reading Materialand a Backup Charger.Even if youre not going up against a decrepit century old transit infrastructure, as a rule, if you leave the house without anything to entertain you, youll end up stuck in a line, waiting room, or traffic indefinitely, bored to tears.No matter how you slice it, keeping some extra battery power on your person can do wonders toRead more Read.Download extra podcasts and articles for offline listening or reading, bring more than one book, and consider backup like a battery case or external battery pack to keep you juiced when several extra hours unexpectedly get added to your trek home.Meditate The horrors and indignities of the subway have been known to serve as a catalyst for spiritual awakenings even before service quality took a nosedive.Mary Karr, for one, has cited wanting to kill everyone on the subway as one of the factors that pushed her towards converting to Catholicism as an adult.Last week, I experienced a panic attack for the first time.The scariest part, though, was that IRead more Read.For a less committed spiritual experience and a means of calming down if youre starting to feel edgy or on the precipice of a panic attack, consider turning to deep breathing exercises, or better yet, transit specific guided meditations.Youtube has a wealth of options geared towards stressed commuters, and meditation apps Headspace and Buddhify both have guided meditations for transit, as well. Comparacion De Modelos De Desarrollo De Software Xp there. Verbally Abuse Andrew Cuomo.While Albany has systematically under funded the MTA for years, Governor Cuomo has made a priority out of relatively low priority glamour projects, such as adding Wi.Fi to every station in the subway station earlier this year.Which means that while youre stuck on an increasingly overheated and crowded subway platform, you can sign right onto that Transit.Wireless. Wifi network, and start firing off tweets MTA and NYCGov.Cuomo letting them know, in extremely specific detail, just how much theyre ruining your day, exactly how you feel about it, and exactly how youll be voting in the next election.Perhaps its more cathartic than effectual, but its garnering attention earlier this summer Cuomo complained, They tweet nasty things about me all day, the riders, but we cant figure out how to communicate with them.One more way to communicate go ahead and give his office a call at 1 5.
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