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docker-mailserver/docs/content/config/best-practices/spf.md

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docs(refactor): Large refactor + additions + fixes Consistency pass, formatting cleanup and fixes, introduce admonitions, add front-matter. --- docs: Add front-matter --- docs: Fix and format links - Some links were invalid (eg files moved or renamed) - Some were valid but had invalid section headers (content removed or migrated) - Some use `http://` instead of `https://` when the website supports a secure connection. - Some already used the `[name][reference]` convention but often with a number that wasn't as useful for maintenance. - All referenced docs needed URLs replaced. Opted for the `[name][reference]` approach to group them all clearly at the bottom of the doc, especially with the relative URLs and in some cases many duplicate entries. - All `tomav` references from the original repo prior to switch to an organization have been corrected. - Minor cosmetic changes to the `name` part of the URL, such as for referencing issues to be consistent. - Some small changes to text body, usually due to duplicate URL reference that was unnecessary (open relay, youtous) - Switched other links to use the `[name][reference]` format when there was a large group of URLs such as wikipedia or kubernetes. Github repos that reference projects related to `docker-mailserver` also got placed here so they're noticed better by maintainers. This also helped quite a bit with `mermaid` external links that are very long. - There was a Github Wiki supported syntax in use `[[name | link]]` for `fetchmail` page that isn't compatible by default with MkDocs (needs a plugin), converted to `[name][reference]` instead since it's a relative link. --- docs: Update commit link for LDAP override script Logic moved to another file, keeping the permalink commit reference so it's unaffected by any changes in the file referenced in future. --- docs: Heading corrections Consistency pass. Helps with the Table of Contents (top-right UI) aka Document Outline. docs: codefence cleanup --- docs: misc cleanup --- docs: Add Admonitions Switches `<details>` usage for collapsible admonitions (`???`) while other text content is switched to the visually more distinct admoniton (`!!!` or `???+`) style. This does affect editor syntax highlighting a bit and markdown linting as it's custom non-standard markdown syntax.
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---
title: 'Best Practices | SPF'
hide:
- toc # Hide Table of Contents for this page
---
Updated Configure SPF (markdown)
2016-04-24 15:55:39 +00:00
From [Wikipedia](https://en.wikipedia.org/wiki/Sender_Policy_Framework):
Updated Configure SPF (markdown)
2016-04-24 15:46:45 +00:00
Created Configure SPF (markdown)
2016-04-24 15:46:33 +00:00
> Sender Policy Framework (SPF) is a simple email-validation system designed to detect email spoofing by providing a mechanism to allow receiving mail exchangers to check that incoming mail from a domain comes from a host authorized by that domain's administrators. The list of authorized sending hosts for a domain is published in the Domain Name System (DNS) records for that domain in the form of a specially formatted TXT record. Email spam and phishing often use forged "from" addresses, so publishing and checking SPF records can be considered anti-spam techniques.
Updated Configure SPF (markdown)
2020-06-01 00:53:42 +00:00
For a more technical review: https://github.com/internetstandards/toolbox-wiki/blob/master/SPF-how-to.md
docs(refactor): Large refactor + additions + fixes Consistency pass, formatting cleanup and fixes, introduce admonitions, add front-matter. --- docs: Add front-matter --- docs: Fix and format links - Some links were invalid (eg files moved or renamed) - Some were valid but had invalid section headers (content removed or migrated) - Some use `http://` instead of `https://` when the website supports a secure connection. - Some already used the `[name][reference]` convention but often with a number that wasn't as useful for maintenance. - All referenced docs needed URLs replaced. Opted for the `[name][reference]` approach to group them all clearly at the bottom of the doc, especially with the relative URLs and in some cases many duplicate entries. - All `tomav` references from the original repo prior to switch to an organization have been corrected. - Minor cosmetic changes to the `name` part of the URL, such as for referencing issues to be consistent. - Some small changes to text body, usually due to duplicate URL reference that was unnecessary (open relay, youtous) - Switched other links to use the `[name][reference]` format when there was a large group of URLs such as wikipedia or kubernetes. Github repos that reference projects related to `docker-mailserver` also got placed here so they're noticed better by maintainers. This also helped quite a bit with `mermaid` external links that are very long. - There was a Github Wiki supported syntax in use `[[name | link]]` for `fetchmail` page that isn't compatible by default with MkDocs (needs a plugin), converted to `[name][reference]` instead since it's a relative link. --- docs: Update commit link for LDAP override script Logic moved to another file, keeping the permalink commit reference so it's unaffected by any changes in the file referenced in future. --- docs: Heading corrections Consistency pass. Helps with the Table of Contents (top-right UI) aka Document Outline. docs: codefence cleanup --- docs: misc cleanup --- docs: Add Admonitions Switches `<details>` usage for collapsible admonitions (`???`) while other text content is switched to the visually more distinct admoniton (`!!!` or `???+`) style. This does affect editor syntax highlighting a bit and markdown linting as it's custom non-standard markdown syntax.
2021-03-01 10:41:19 +00:00
## Add a SPF Record
Updated Configure SPF (markdown)
2020-06-01 00:54:02 +00:00
Created Configure SPF (markdown)
2016-04-24 15:46:33 +00:00
To add a SPF record in your DNS, insert the following line in your DNS zone:
docs(refactor): Large refactor + additions + fixes Consistency pass, formatting cleanup and fixes, introduce admonitions, add front-matter. --- docs: Add front-matter --- docs: Fix and format links - Some links were invalid (eg files moved or renamed) - Some were valid but had invalid section headers (content removed or migrated) - Some use `http://` instead of `https://` when the website supports a secure connection. - Some already used the `[name][reference]` convention but often with a number that wasn't as useful for maintenance. - All referenced docs needed URLs replaced. Opted for the `[name][reference]` approach to group them all clearly at the bottom of the doc, especially with the relative URLs and in some cases many duplicate entries. - All `tomav` references from the original repo prior to switch to an organization have been corrected. - Minor cosmetic changes to the `name` part of the URL, such as for referencing issues to be consistent. - Some small changes to text body, usually due to duplicate URL reference that was unnecessary (open relay, youtous) - Switched other links to use the `[name][reference]` format when there was a large group of URLs such as wikipedia or kubernetes. Github repos that reference projects related to `docker-mailserver` also got placed here so they're noticed better by maintainers. This also helped quite a bit with `mermaid` external links that are very long. - There was a Github Wiki supported syntax in use `[[name | link]]` for `fetchmail` page that isn't compatible by default with MkDocs (needs a plugin), converted to `[name][reference]` instead since it's a relative link. --- docs: Update commit link for LDAP override script Logic moved to another file, keeping the permalink commit reference so it's unaffected by any changes in the file referenced in future. --- docs: Heading corrections Consistency pass. Helps with the Table of Contents (top-right UI) aka Document Outline. docs: codefence cleanup --- docs: misc cleanup --- docs: Add Admonitions Switches `<details>` usage for collapsible admonitions (`???`) while other text content is switched to the visually more distinct admoniton (`!!!` or `???+`) style. This does affect editor syntax highlighting a bit and markdown linting as it's custom non-standard markdown syntax.
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```txt
; MX record must be declared for SPF to work
domain.com. IN MX 1 mail.domain.com.
Created Configure SPF (markdown)
2016-04-24 15:46:33 +00:00
docs(refactor): Large refactor + additions + fixes Consistency pass, formatting cleanup and fixes, introduce admonitions, add front-matter. --- docs: Add front-matter --- docs: Fix and format links - Some links were invalid (eg files moved or renamed) - Some were valid but had invalid section headers (content removed or migrated) - Some use `http://` instead of `https://` when the website supports a secure connection. - Some already used the `[name][reference]` convention but often with a number that wasn't as useful for maintenance. - All referenced docs needed URLs replaced. Opted for the `[name][reference]` approach to group them all clearly at the bottom of the doc, especially with the relative URLs and in some cases many duplicate entries. - All `tomav` references from the original repo prior to switch to an organization have been corrected. - Minor cosmetic changes to the `name` part of the URL, such as for referencing issues to be consistent. - Some small changes to text body, usually due to duplicate URL reference that was unnecessary (open relay, youtous) - Switched other links to use the `[name][reference]` format when there was a large group of URLs such as wikipedia or kubernetes. Github repos that reference projects related to `docker-mailserver` also got placed here so they're noticed better by maintainers. This also helped quite a bit with `mermaid` external links that are very long. - There was a Github Wiki supported syntax in use `[[name | link]]` for `fetchmail` page that isn't compatible by default with MkDocs (needs a plugin), converted to `[name][reference]` instead since it's a relative link. --- docs: Update commit link for LDAP override script Logic moved to another file, keeping the permalink commit reference so it's unaffected by any changes in the file referenced in future. --- docs: Heading corrections Consistency pass. Helps with the Table of Contents (top-right UI) aka Document Outline. docs: codefence cleanup --- docs: misc cleanup --- docs: Add Admonitions Switches `<details>` usage for collapsible admonitions (`???`) while other text content is switched to the visually more distinct admoniton (`!!!` or `???+`) style. This does affect editor syntax highlighting a bit and markdown linting as it's custom non-standard markdown syntax.
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; SPF record
domain.com. IN TXT "v=spf1 mx ~all"
```
Created Configure SPF (markdown)
2016-04-24 15:46:33 +00:00
Updated Configure SPF (markdown)
2020-06-01 00:31:12 +00:00
This enables the _Softfail_ mode for SPF. You could first add this SPF record with a very low TTL.
_SoftFail_ is a good setting for getting started and testing, as it lets all email through, with spams tagged as such in the mailbox.
Updated Configure SPF (markdown)
2019-08-23 18:31:33 +00:00
docs(refactor): Large refactor + additions + fixes Consistency pass, formatting cleanup and fixes, introduce admonitions, add front-matter. --- docs: Add front-matter --- docs: Fix and format links - Some links were invalid (eg files moved or renamed) - Some were valid but had invalid section headers (content removed or migrated) - Some use `http://` instead of `https://` when the website supports a secure connection. - Some already used the `[name][reference]` convention but often with a number that wasn't as useful for maintenance. - All referenced docs needed URLs replaced. Opted for the `[name][reference]` approach to group them all clearly at the bottom of the doc, especially with the relative URLs and in some cases many duplicate entries. - All `tomav` references from the original repo prior to switch to an organization have been corrected. - Minor cosmetic changes to the `name` part of the URL, such as for referencing issues to be consistent. - Some small changes to text body, usually due to duplicate URL reference that was unnecessary (open relay, youtous) - Switched other links to use the `[name][reference]` format when there was a large group of URLs such as wikipedia or kubernetes. Github repos that reference projects related to `docker-mailserver` also got placed here so they're noticed better by maintainers. This also helped quite a bit with `mermaid` external links that are very long. - There was a Github Wiki supported syntax in use `[[name | link]]` for `fetchmail` page that isn't compatible by default with MkDocs (needs a plugin), converted to `[name][reference]` instead since it's a relative link. --- docs: Update commit link for LDAP override script Logic moved to another file, keeping the permalink commit reference so it's unaffected by any changes in the file referenced in future. --- docs: Heading corrections Consistency pass. Helps with the Table of Contents (top-right UI) aka Document Outline. docs: codefence cleanup --- docs: misc cleanup --- docs: Add Admonitions Switches `<details>` usage for collapsible admonitions (`???`) while other text content is switched to the visually more distinct admoniton (`!!!` or `???+`) style. This does affect editor syntax highlighting a bit and markdown linting as it's custom non-standard markdown syntax.
2021-03-01 10:41:19 +00:00
After verification, you _might_ want to change your SPF record to `v=spf1 mx -all` so as to enforce the _HardFail_ policy. See http://www.open-spf.org/SPF_Record_Syntax for more details about SPF policies.
Updated Configure SPF (markdown)
2019-08-23 18:31:33 +00:00
Updated Configure SPF (markdown)
2020-06-01 00:31:12 +00:00
In any case, increment the SPF record's TTL to its final value.
Updated Configure SPF (markdown)
2018-02-09 21:16:48 +00:00
## Backup MX, Secondary MX
docs(refactor): Large refactor + additions + fixes Consistency pass, formatting cleanup and fixes, introduce admonitions, add front-matter. --- docs: Add front-matter --- docs: Fix and format links - Some links were invalid (eg files moved or renamed) - Some were valid but had invalid section headers (content removed or migrated) - Some use `http://` instead of `https://` when the website supports a secure connection. - Some already used the `[name][reference]` convention but often with a number that wasn't as useful for maintenance. - All referenced docs needed URLs replaced. Opted for the `[name][reference]` approach to group them all clearly at the bottom of the doc, especially with the relative URLs and in some cases many duplicate entries. - All `tomav` references from the original repo prior to switch to an organization have been corrected. - Minor cosmetic changes to the `name` part of the URL, such as for referencing issues to be consistent. - Some small changes to text body, usually due to duplicate URL reference that was unnecessary (open relay, youtous) - Switched other links to use the `[name][reference]` format when there was a large group of URLs such as wikipedia or kubernetes. Github repos that reference projects related to `docker-mailserver` also got placed here so they're noticed better by maintainers. This also helped quite a bit with `mermaid` external links that are very long. - There was a Github Wiki supported syntax in use `[[name | link]]` for `fetchmail` page that isn't compatible by default with MkDocs (needs a plugin), converted to `[name][reference]` instead since it's a relative link. --- docs: Update commit link for LDAP override script Logic moved to another file, keeping the permalink commit reference so it's unaffected by any changes in the file referenced in future. --- docs: Heading corrections Consistency pass. Helps with the Table of Contents (top-right UI) aka Document Outline. docs: codefence cleanup --- docs: misc cleanup --- docs: Add Admonitions Switches `<details>` usage for collapsible admonitions (`???`) while other text content is switched to the visually more distinct admoniton (`!!!` or `???+`) style. This does affect editor syntax highlighting a bit and markdown linting as it's custom non-standard markdown syntax.
2021-03-01 10:41:19 +00:00
For whitelisting a IP Address from the SPF test, you can create a config file (see [`policyd-spf.conf`](https://www.linuxcertif.com/man/5/policyd-spf.conf)) and mount that file into `/etc/postfix-policyd-spf-python/policyd-spf.conf`.
Updated Configure SPF (markdown)
2018-02-09 21:16:48 +00:00
**Example:**
docs(refactor): Large refactor + additions + fixes Consistency pass, formatting cleanup and fixes, introduce admonitions, add front-matter. --- docs: Add front-matter --- docs: Fix and format links - Some links were invalid (eg files moved or renamed) - Some were valid but had invalid section headers (content removed or migrated) - Some use `http://` instead of `https://` when the website supports a secure connection. - Some already used the `[name][reference]` convention but often with a number that wasn't as useful for maintenance. - All referenced docs needed URLs replaced. Opted for the `[name][reference]` approach to group them all clearly at the bottom of the doc, especially with the relative URLs and in some cases many duplicate entries. - All `tomav` references from the original repo prior to switch to an organization have been corrected. - Minor cosmetic changes to the `name` part of the URL, such as for referencing issues to be consistent. - Some small changes to text body, usually due to duplicate URL reference that was unnecessary (open relay, youtous) - Switched other links to use the `[name][reference]` format when there was a large group of URLs such as wikipedia or kubernetes. Github repos that reference projects related to `docker-mailserver` also got placed here so they're noticed better by maintainers. This also helped quite a bit with `mermaid` external links that are very long. - There was a Github Wiki supported syntax in use `[[name | link]]` for `fetchmail` page that isn't compatible by default with MkDocs (needs a plugin), converted to `[name][reference]` instead since it's a relative link. --- docs: Update commit link for LDAP override script Logic moved to another file, keeping the permalink commit reference so it's unaffected by any changes in the file referenced in future. --- docs: Heading corrections Consistency pass. Helps with the Table of Contents (top-right UI) aka Document Outline. docs: codefence cleanup --- docs: misc cleanup --- docs: Add Admonitions Switches `<details>` usage for collapsible admonitions (`???`) while other text content is switched to the visually more distinct admoniton (`!!!` or `???+`) style. This does affect editor syntax highlighting a bit and markdown linting as it's custom non-standard markdown syntax.
2021-03-01 10:41:19 +00:00
Create and edit a `policyd-spf.conf` file here `/<your docker-mailserver dir>/config/postfix-policyd-spf.conf`:
```conf
debugLevel = 1
Updated Configure SPF (markdown)
2018-02-09 21:16:48 +00:00
#0(only errors)-4(complete data received)
skip_addresses = 127.0.0.0/8,::ffff:127.0.0.0/104,::1
# Preferably use IP-Addresses for whitelist lookups:
Whitelist = 192.168.0.0/31,192.168.1.0/30
# Domain_Whitelist = mx1.mybackupmx.com,mx2.mybackupmx.com
```
docs(refactor): Large refactor + additions + fixes Consistency pass, formatting cleanup and fixes, introduce admonitions, add front-matter. --- docs: Add front-matter --- docs: Fix and format links - Some links were invalid (eg files moved or renamed) - Some were valid but had invalid section headers (content removed or migrated) - Some use `http://` instead of `https://` when the website supports a secure connection. - Some already used the `[name][reference]` convention but often with a number that wasn't as useful for maintenance. - All referenced docs needed URLs replaced. Opted for the `[name][reference]` approach to group them all clearly at the bottom of the doc, especially with the relative URLs and in some cases many duplicate entries. - All `tomav` references from the original repo prior to switch to an organization have been corrected. - Minor cosmetic changes to the `name` part of the URL, such as for referencing issues to be consistent. - Some small changes to text body, usually due to duplicate URL reference that was unnecessary (open relay, youtous) - Switched other links to use the `[name][reference]` format when there was a large group of URLs such as wikipedia or kubernetes. Github repos that reference projects related to `docker-mailserver` also got placed here so they're noticed better by maintainers. This also helped quite a bit with `mermaid` external links that are very long. - There was a Github Wiki supported syntax in use `[[name | link]]` for `fetchmail` page that isn't compatible by default with MkDocs (needs a plugin), converted to `[name][reference]` instead since it's a relative link. --- docs: Update commit link for LDAP override script Logic moved to another file, keeping the permalink commit reference so it's unaffected by any changes in the file referenced in future. --- docs: Heading corrections Consistency pass. Helps with the Table of Contents (top-right UI) aka Document Outline. docs: codefence cleanup --- docs: misc cleanup --- docs: Add Admonitions Switches `<details>` usage for collapsible admonitions (`???`) while other text content is switched to the visually more distinct admoniton (`!!!` or `???+`) style. This does affect editor syntax highlighting a bit and markdown linting as it's custom non-standard markdown syntax.
2021-03-01 10:41:19 +00:00
Then add this line to `docker-compose.yml`:
Updated Configure SPF (markdown)
2018-02-09 21:16:48 +00:00
```yaml
docs(refactor): Large refactor + additions + fixes Consistency pass, formatting cleanup and fixes, introduce admonitions, add front-matter. --- docs: Add front-matter --- docs: Fix and format links - Some links were invalid (eg files moved or renamed) - Some were valid but had invalid section headers (content removed or migrated) - Some use `http://` instead of `https://` when the website supports a secure connection. - Some already used the `[name][reference]` convention but often with a number that wasn't as useful for maintenance. - All referenced docs needed URLs replaced. Opted for the `[name][reference]` approach to group them all clearly at the bottom of the doc, especially with the relative URLs and in some cases many duplicate entries. - All `tomav` references from the original repo prior to switch to an organization have been corrected. - Minor cosmetic changes to the `name` part of the URL, such as for referencing issues to be consistent. - Some small changes to text body, usually due to duplicate URL reference that was unnecessary (open relay, youtous) - Switched other links to use the `[name][reference]` format when there was a large group of URLs such as wikipedia or kubernetes. Github repos that reference projects related to `docker-mailserver` also got placed here so they're noticed better by maintainers. This also helped quite a bit with `mermaid` external links that are very long. - There was a Github Wiki supported syntax in use `[[name | link]]` for `fetchmail` page that isn't compatible by default with MkDocs (needs a plugin), converted to `[name][reference]` instead since it's a relative link. --- docs: Update commit link for LDAP override script Logic moved to another file, keeping the permalink commit reference so it's unaffected by any changes in the file referenced in future. --- docs: Heading corrections Consistency pass. Helps with the Table of Contents (top-right UI) aka Document Outline. docs: codefence cleanup --- docs: misc cleanup --- docs: Add Admonitions Switches `<details>` usage for collapsible admonitions (`???`) while other text content is switched to the visually more distinct admoniton (`!!!` or `???+`) style. This does affect editor syntax highlighting a bit and markdown linting as it's custom non-standard markdown syntax.
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volumes:
- ./config/postfix-policyd-spf.conf:/etc/postfix-policyd-spf-python/policyd-spf.conf
```
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