all-in-one privacy solution":["Proton Unlimited es una solución de privacidad todo en uno"],"Black Friday":["Black Friday"],"No ads. Privacy by default.":["Sin anuncios. Privacidad por defecto."],"People before profits":["Primero las personas, luego los beneficios"],"Security through transparency":["Seguridad con transparencia"],"The best Proton Mail ${ BLACK_FRIDAY } deals":["Las mejores ofertas de Proton Mail en el ${ BLACK_FRIDAY }"],"The world’s only community- supported email service":["El único servicio de correo electrónico del mundo respaldado por la comunidad"]},"specialoffer:limited":{"${ hours } hour":["${ hours } hora","${ hours } horas"],"${ hoursLeft }, ${ minutesLeft } and ${ secondsLeft } left":["Tiempo restante: ${ hoursLeft }, ${ minutesLeft } y ${ secondsLeft }"],"${ minutes } minute":["${ minutes } minuto","${ minutes } minutos"],"${ seconds } second":["${ seconds } segundo","${ seconds } segundos"],"Limited time offer":["Oferta por tiempo limitado"]},"specialoffer:listitem":{"Create multiple addresses":["Cree múltiples direcciones"],"Hide-my-email aliases":["Seudónimos de hide-my-email"],"Quickly unsubscribe from newsletters":["Cancele suscripciones a boletines rápidamente"],"Use your own domain name":["Use su propio dominio"]},"specialoffer:logos":{"As featured in":["Tal como aparece en"]},"specialoffer:metadescription":{"Get an encrypted email that protects your privacy":["Obtenga un correo electrónico cifrado que protege su privacidad"]},"specialoffer:metatitle":{"Proton Mail Black Friday Sale - Up to 40% off":["Oferta de Black Friday de Proton Mail: hasta un 40% de descuento"]},"specialoffer:newmetadescription":{"Get up to 40% off Proton Mail subscriptions this Black Friday. Find great deals on our secure end-to-end encrypted email plans.":["Aproveche las rebajas de Black Friday y obtenga suscripciones de Proton Mail con hasta un 40 % de descuento. Encontrará las mejores ofertas en planes de correo electrónico seguro cifrado de extremo a extremo."]},"specialoffer:newmetatitle":{"Proton Mail Black Friday sale | Up to 40% off secure email":["Rebajas de Black Friday en Proton Mail | Hasta un 40 % de descuento en correo electrónico seguro"]},"specialoffer:note":{"* Billed at ${ TOTAL_SUM } for the first year":["*Con un costo de ${ TOTAL_SUM } durante el primer año"],"*Billed at ${ TOTAL_SUM } for the first 2 years":["*Con un costo de ${ TOTAL_SUM } durante los primeros 2 años"],"30-day money-back guarantee":["Garantía de devolución de dinero de 30 días"],"Billed at ${ TOTAL_SUM } for the first 2 years":["Con un costo de ${ TOTAL_SUM } durante los primeros 2 años"],"Billed at ${ TOTAL_SUM } for the first year":["Con un costo de ${ TOTAL_SUM } durante el primer año"],"You save ${ SAVE_SUM }":["Ahorre ${ SAVE_SUM }"]},"specialoffer:off":{"${ DISCOUNT } off":["-${ DISCOUNT }"],"${ PERCENT_OFF } off":["-${ PERCENT_OFF }"]},"specialoffer:testimonial":{"I love my ProtonMail":["Amo mi Proton Mail"],"My favorite email service":["Mi servicio de correo electrónico favorito"],"Thanks Proton for keeping us all safe in the complicated internet universe.":["Gracias Proton por mantenernos a salvo en el complicado universo de Internet."],"You get what you pay for. In the case of big tech, if you pay nothing, you get used. I quit using Gmail and switched to @ProtonMail":["Obtiene aquello por lo que paga. En el caso de la gran tecnología, cuando uno no paga nada, se acostumbra. Dejé de usar Gmail y cambié a @ProtonMail"]},"specialoffer:time":{"Days":["Días"],"Hours":["Horas"],"Min":["min"]},"specialoffer:title":{"And much more":["Y mucho más"],"Make your inbox yours":["Personalice su bandeja de entrada"],"Safe from trackers":["A salvo de rastreadores"],"Stay organized":["Mantenga el orden"],"Black Friday email deals":["Ofertas en correo electrónico del Black Friday"],"Don’t just take our word for it":["No confíe solo en nuestra palabra"],"Our story":["Nuestra historia"],"Transfer your data from Google in one click":["Transfiera sus datos de Google con un solo clic"]},"specialoffer:tooltip":{"Access blocked content and browse privately. Includes ${ TOTAL_SERVERS }+ servers in ${ TOTAL_COUNTRIES }+ countries, connect up to 10 devices, access worldwide streaming services, malware and ad-blocker, and more.":["Acceda a contenido bloqueado y navegue de forma privada. Incluye ${ TOTAL_SERVERS } servidores en más de ${ TOTAL_COUNTRIES } países, conecta hasta 10 dispositivos, acceda a servicios de transmisión en todo el mundo, malware y bloqueador de anuncios, y más."],"Easily share your calendar with your family, friends or colleagues, and view external calendars.":["Comparta su calendario con familiares, amigos y compañeros fácilmente y consulte calendarios externos."],"Includes support for 1 custom email domain, 10 email addresses, 10 hide-my-email aliases, calendar sharing, and more.":["Incluye compatibilidad con 1 dominio de correo electrónico personalizado, 10 direcciones de correo electrónico, 10 seudónimos de hide-my-email, posibilidad de compartir calendario, etc."],"Includes support for 3 custom email domains, 15 email addresses, unlimited hide-my-email aliases, calendar sharing, and more.":["Incluye compatibilidad con 3 dominios de correo electrónico personalizado, 15 direcciones de correo electrónico, seudónimos ilimitados de hide-my-email, posibilidad de compartir calendario, etc."],"Manage up to 25 calendars, mobile apps, secured with end-to-end encryption, 1-click calendar import from Google, and more.":["Administre hasta 25 calendarios, apps móviles, protegido con cifrado de extremo a extremo, importación de calendario con 1 clic desde Google y más."]},"Status Banner":{"At the moment we are experiencing issues with the Proton VPN service":["En este momento, tenemos problemas con el servicio Proton VPN."],"Learn more":["Más información"]},"Status banner":{"Learn more":["Más información"],"Please note that at the moment we are experiencing issues with the ${ issues[0] } service.":["Tenga en cuenta que, en este momento, estamos experimentando problemas con el servicio ${ issues[0] }."],"We are experiencing issues with one or more services at the moment.":["En este momento, tenemos problemas con uno o más servicios."]},"suggestions":{"Suggestions":["Sugerencias"]},"Support":{"Sub category":["Subacategoria","Subcategorías"]},"Support article":{"${ readingTime } min":["${ readingTime } minuto","${ readingTime } minutos"],"Category":["Categoría","Categorías"],"Didn’t find what you were looking for?":["¿No encontró lo que buscaba?"],"General contact":["Contacto general"],"Get help":["Obtener ayuda"],"Legal contact":["Contacto legal"],"Media contact":["Contacto para medios"],"Partnerships contact":["Contacto para colaboradores"],"Reading":["Lectura"]},"Support categories":{"Browse Proton product support":["Explore el soporte de productos de Proton"]},"Support category":{"There is no article in this category yet.":["Todavía no hay ningún artículo en esta categoría."]},"Support troubleshooting":{"--- Select ---":["--- Seleccionar ---"],"App version":["Versión de la app"],"Browser":["Navegador"],"Check if this helps":["Compruebe si le sirve"],"Choose a category for your question":["Elija la categoría de su pregunta"],"Choose a product":["Elija un producto"],"Did this solve your issue ?":["¿Resolvió su problema?"],"Faster assistance is just a few clicks away — please make your selections":["Obtenga ayuda más rápidamente con tan solo unos clics. Haga su selección."],"No, contact support":["No, contactar a soporte"],"Proton account":["Cuenta de Proton"],"Proton Bridge":["Proton Bridge"],"Proton Calendar":["Calendario de Proton"],"Proton Drive":["Proton Drive"],"Proton for Business":["Proton for Business"],"Proton Mail":["Correo de Proton"],"Proton Pass":["Proton Pass"],"Proton VPN":["VPN de Proton"],"Thank you for your feedback":["Gracias por sus comentarios"],"Troubleshooting":["Solución de problemas"],"What can we help with ?":["¿En qué podemos ayudar?"],"Yes":["Sí"]},"support_modal_search_query":{"Search query":["Consulta"]},"support_search_button":{"Search":["Buscar"]},"support_search_i_am_looking_for":{"I'm looking for":["Busco"]},"SupportForm":{"For a faster resolution, please report the issue from the Bridge app: Help > Report a problem.":["Para una resolución más rápida, reporte el problema desde la app Bridge: Ayuda > Reportar un problema."],"Information":["Información"]},"SupportForm:option":{"Account Security":["Seguridad de la cuenta"],"Contacts":["Contactos"],"Custom email domain":["Dominio de correo electrónico personalizado"],"Email delivery and Spam":["Entrega de correo electrónico y spam"],"Encryption":["Cifrado"],"Login and password":["Inicio de sesión y contraseña"],"Merge aliases and accounts":["Combinar alias y cuentas"],"Migrate to Proton":["Migrar a Proton"],"Notifications":["Notificaciones"],"Other":["Otros"],"Plans and billing":["Planes y facturación"],"Proton for Business":["Proton for Business"],"Sign up":["Regístrese"],"Storage":["Almacenamiento"],"Users, addresses, and identities":["Usuarios, direcciones e identidades"]},"SupportForm:optionIntro":{"Select a topic":["Seleccione un tema"]},"swiss_baseed_feature":{"Swiss based":["Con sede en Suiza"]},"Testimonial":{"Awards":["Premios"],"Customers":["Clientes"],"Featured":["Destacados"],"Go to testimonial source":["Ir a la fuente testimonial"],"Reviews":["Reseñas"],"Videos":["Videos"]},"Text":{"Find the plan that's right for you":["Encuentre el plan adecuado para usted"],"If you need help, check out our ${ supportLink }.":["Si necesita ayuda, consulte nuestra ${ supportLink }."],"The page you’re looking for might have been removed, or it could be an\nold link.":["Es posible que la página que busca haya sido eliminada o que sea un\nenlace antiguo."]},"Title":{"On this page":["En esta página"],"Related articles":["Artículos relacionados"],"Share ${ thisPage }":["Compartir ${ thisPage }"],"Thank you!":["¡Gracias!"],"this page":["esta página"]},"Tooltip":{"More information":["Más información"]},"tooltip_calendar":{"Create up to 20 custom & shareable encrypted calendars. On top of that, add up to 5 calendars from friends, family, colleagues, and organizations.":["Cree hasta 20 calendarios personalizados, compartibles y cifrados. Agregue hasta 5 calendarios de amigos, familiares, colegas y organizaciones."]},"tooltip_vpn":{"Access blocked content and browse privately. Includes ${ TOTAL_SERVERS }+ servers in ${ TOTAL_COUNTRIES }+ countries, highest VPN speed, ${ TOTAL_VPN_CONNECTIONS } VPN connections, worldwide streaming services, malware and ad-blocker, and more.":["Acceda a contenido bloqueado y navegue en privado. Tendrá a su disposición más de ${ TOTAL_SERVERS } servidores en más de ${ TOTAL_COUNTRIES } países, VPN de máxima velocidad, ${ TOTAL_VPN_CONNECTIONS } conexiones VPN, servicios de streaming en todo el mundo, bloqueadores de malware y de anuncios, y mucho más."],"Access blocked content and browse privately. Includes ${ TOTAL_SERVERS }+ servers in ${ TOTAL_COUNTRIES }+ countries, highest VPN speed, 10 VPN connections, worldwide streaming services, malware and ad-blocker, and more.":["Acceda a contenido bloqueado y navegue en privado. Tendrá a su disposición más de ${ TOTAL_SERVERS } servidores en más de ${ TOTAL_COUNTRIES } países, VPN de máxima velocidad, 10 conexiones VPN, servicios de streaming en todo el mundo, bloqueadores de malware y de anuncios, y mucho más."]},"version_history_label":{"Version history":["Historial de versiones"]},"version_history_tooltip":{"Store up to ${ versionHistoryNumber } versions of each file for up to ${ years } years":["Comparta hasta ${ versionHistoryNumber } versiones de cada archivo hasta durante ${ years } años"]},"vpn_features_link":{"View VPN plans":["Ver planes de VPN"]},"vpn_features_useCase":{"Access blocked content and browse privately":["Acceda a contenido bloqueado y navegue de forma privada"]}}},"unleashApi":"https://account.proton.me/api"};
// We need to import data (the framework context) from the server
// This Astro feature with define:vars works well but creates an inline script
// So we can't directly import the initFramework helper, we have to store the context
window.frameworkContext = frameworkContext;
})();
Sender Policy Framework (SPF) is an email authentication method that verifies that a message has been sent from an authorized mail server. Learn how it works and how it helps to protect your email domain.
Sender Policy Framework (SPF) is an email authentication protocol that allows you to specify the servers authorized to send mail from your domain, making it harder for fraudsters to spoof(new window) (forge) your address.
If you send email from a custom domain (for example, @yourdomain.com), you can list the IP addresses(new window) of the mail servers authorized to send your mail. By checking your list of IP addresses, email services and ISPs can identify whether the message came from a trusted server.
What is SPF used for?
SPF is one of the main methods email servers use to authenticate emails. It helps email providers identify spoofed addresses and block spam and phishing emails.
However, SPF alone isn’t enough to spot spoofed messages(new window) because the sender’s address (From field) can be forged. By using SPF with DKIM and DMARC, email providers can verify that the sender’s domain matches the From field, confirming that the address isn’t spoofed.
How SPF differs from DKIM and DMARC
SPF, DKIM, and DMARC are email authentication protocols that are used to verify that emails are sent from a legitimate sender, but they all work differently. Here’s how they work together:
SPF (Sender Policy Framework) verifies that an email has been sent from an IP address authorized to send emails from the sender’s domain.
SPF checks whether an incoming email has been sent from a mail server authorized to send mail from that domain.
First, you must create an SPF record that lists the IP addresses of the mail servers authorized to send mail from your domain. Then you’re ready to send messages with SPF as follows:
You send an email, for example, from the address you@yourdomain.com. Suppose the message is sent from one of your authorized email servers with the IP address 185.70.40.111.
When the email arrives, the receiving mail server checks the sender’s address in the Return-Path (also known as MAIL FROM) field of the email header(new window) and looks up the SPF record for your domain (in this example, yourdomain.com).
The receiving mail server checks whether the IP address from which the mail was sent (185.70.40.111) is listed in your SPF record.
If the IP address is listed, the message passes SPF; if it isn’t, it fails.
Note that in step 2. the receiving mail server looks up the SPF record for the domain in the Return-Path field, which doesn’t need to be the same as the domain in the From field. Even if the domain in the From address is spoofed and differs from that in the Return-Path, a message can pass SPF.
That’s why you need DMARC to verify that the domain in the SPF and DKIM checks matches the sender’s address in the From field.
What is an SPF record?
An SPF record is a type of DNS text record(new window) that lists the IP addresses of the servers authorized to send email from a particular domain. SPF records are published on the domain’s DNS server, so any receiving mail server can look up the list to check whether an email has been sent from a trusted server.
SPF record example
Here’s an example of an SPF record with an explanation of what it means below:
v=spf1: The SPF version number. Every SPF record must begin with this tag.
ip4: The IP address(es) of the servers authorized to send email from your domain. They can be IPv4 or IPv6 addresses(new window); IPv6 addresses use the tag ip6.
include: Instructs the server to check the SPF records of the additional domain mentioned. In this example, the server would look up _spf.protonmail.ch and add the IP addresses found there to the list of authorized addresses.
mx: Any IP addresses that match the mail servers listed in the MX records(new window) of the sending domain. For example, Proton Mail uses mail.protonmail.ch and mailsec.protonmail.ch.
~all: Tells receiving email servers what to do if an email doesn’t pass SPF. The three most common all tags are:
~all: Mark the message as suspicious
–all: Reject the message
?all: Receiving email server decides (neutral recommendation)
However, since the introduction of DMARC, many email providers, including Proton Mail, no longer use these all tags. Apart from checking that the From field matches the domain in SPF and DKIM checks, DMARC tells servers what to do with messages that fail these checks, making the all tags redundant.
In the example above, the SPF record authorizes mail to be sent from:
185.70.40.111
The IP addresses found in _spf.protonmail.ch
The IP addresses of the mail servers listed in the domain’s MX records
If an email from this domain is received from an IP address not listed above, the message fails SPF and is treated as suspicious.
SPF and mail forwarding
One limitation of SPF is that it doesn’t work reliably with forwarded emails.
When forwarding a message, if the sending mail server replaces the original sender’s email address in the Return-Path (MAIL FROM) field with the forwarder’s address, the receiving server will check the SPF record of the forwarder’s domain. In this case, the message should pass SPF.
But not all email platforms rewrite the Return-Path field when forwarding. If the mail server preserves the original sender’s address in the Return-Path field, the receiving mail server will check the original sender’s SPF record. As this doesn’t include the IP address of the forwarding server, the message fails.
Fortunately, if an email fails SPF, it may still pass the DKIM check because DKIM verifies a message’s content, not its sending IP address. As long as you don’t change the content and structure of the original message, it should pass DKIM.
Why use SPF?
Along with DKIM(new window) and DMARC(new window), SPF is one of the main ways you can protect your domain and ensure your emails get delivered. Here’s why you should use it:
Beat spammers and scammers
SPF makes it harder for cybercriminals to send messages pretending to be from your domain (email spoofing(new window)). Specifying trusted mail servers with SPF helps to prevent fraudsters from using your domain for spam and phishing attacks.
Improve email deliverability
SPF helps ISPs and email platforms identify legitimate emails. So using SPF increases the chances of your messages being delivered instead of ending up in the spam folder.
Boost your domain reputation
The more your emails pass authentication checks like SPF, the more you improve your domain’s reputation with email platforms. So SPF can help improve your emails’ deliverability in the long run.
Easy SPF authentication with Proton Mail
If you have your own domain, we strongly recommend setting up SPF, together with DKIM(new window) and DMARC, to improve your email security and deliverability.
Get Proton Mail Plus for a single domain, or get Proton Unlimited with support for three domains, 15 addresses, 500 GB of storage, and unlimited hide-my-email aliases.
Secure, seamless communication is the foundation of every business. As more
organizations secure their data with Proton, we’ve dramatically expanded our
ecosystem with new products and services, from our password manager to Dark Web
Monitoring for cr
On the subject of cybersecurity, one term that often comes up is brute force
attack. A brute force attack is any attack that doesn’t rely on finesse, but
instead uses raw computing power to crack security or even the underlying
encryption.
In this a
Section 702 of the Foreign Intelligence Surveillance Act has become notorious as
the legal justification allowing federal agencies like the NSA, CIA, and FBI to
perform warrantless wiretaps, which sweep up the data of hundreds of thousands
of US citi
In response to the growing number of data breaches, Proton Mail offers a feature
to paid subscribers called Dark Web Monitoring. Our system checks if your
credentials or other data have been leaked to illegal marketplaces and alerts
you if so. Often
Your email address is your online identity, and you share it whenever you create
a new account for an online service. While this offers convenience, it also
leaves your identity exposed if hackers manage to breach the services you use.
Data breaches
Our mission at Proton is to help usher in an internet that protects your privacy
by default, secures your data, and gives you the freedom of choice.
Today we’re taking another step in this direction with the launch of our open
source password manage