PreMailer.Net
2.7.0
dotnet add package PreMailer.Net --version 2.7.0
NuGet\Install-Package PreMailer.Net -Version 2.7.0
<PackageReference Include="PreMailer.Net" Version="2.7.0" />
<PackageVersion Include="PreMailer.Net" Version="2.7.0" />
<PackageReference Include="PreMailer.Net" />
paket add PreMailer.Net --version 2.7.0
#r "nuget: PreMailer.Net, 2.7.0"
#addin nuget:?package=PreMailer.Net&version=2.7.0
#tool nuget:?package=PreMailer.Net&version=2.7.0
PreMailer.Net

C# Library for moving CSS to inline style attributes, to gain maximum E-mail client compatibility.
Usage
Static method on PreMailer
class
string htmlSource = File.ReadAllText(@"C:\Workspace\testmail.html");
var result = PreMailer.MoveCssInline(htmlSource);
result.Html // Resultant HTML, with CSS in-lined.
result.Warnings // string[] of any warnings that occurred during processing.
Set up PreMailer
instance
string htmlSource = File.ReadAllText(@"C:\Workspace\testmail.html");
var pm = new PreMailer(htmlSource);
// Optional to add analytics tags
pm.AddAnalyticsTags(source, medium, campaign, content, domain = null);
var result = pm.MoveCssInline(
removeStyleElements: false,
ignoreElements: "#ignore",
preserveMediaQueries: true
);
result.Html // Resultant HTML, with CSS in-lined.
result.Warnings // List<string> of any warnings that occurred during processing.
Options
The following options can be passed to the PreMailer.MoveCssInline
method to configure its behavior:
baseUri(Uri = null)
- Base URL to apply tolink
elements withhref
values ending with.css
.removeStyleElements(bool = false)
- Removes elements that were used to source CSS (currently, onlystyle
is supported).ignoreElements(string = null)
- CSS selector of element(s) not to inline. Useful for mobile styles (see below).css(string = null)
- A string containing a style-sheet for inlining.stripIdAndClassAttributes(bool = false)
- True to strip ID and class attributes.removeComments(bool = false)
- True to remove comments, false to leave them intact.customFormatter(IMarkupFormatter = null)
- Custom formatter to use for the HTML output.preserveMediaQueries(bool = false)
- If true and removeStyleElements is true, it will preserve media queries in the style node while removing other CSS, instead of removing the entire style node.useEmailFormatter(bool = false)
- If true, empty HTML tags will be preserved as full tags instead of being converted to self-closing tags, and HTML entities like © will be preserved.
External style sheets
Sometimes it's handy to reference external style sheets with a <link href="..." />
element. PreMailer will download and use external style sheets as long as the value of href
ends with .css
.
Both absolute and relative URLs are supported. If the URL is relative, you must specify the baseUri
parameter in either the constructor, or when calling the static MoveCssInline
method.
<link />
elements that match the ignoreElements
selector won't be downloaded.
Media queries
If you want to apply mobile styles to your e-mail, you should put your
mobile specific styles in its own style
block that targets the appropriate devices using media queries.
But since you cannot know by the time of sending an e-mail whether or not it will be viewed on a mobile device, the style
block that targets mobile devices should not be inlined!
To ignore a style
block, you need to specify an ignore selector when calling the MoveCssInline
method, like this:
var result = PreMailer.MoveCssInline(input, false, ignoreElements: "#ignore");
Alternatively, you can use the preserveMediaQueries
parameter to keep your media queries while removing other styles:
var result = PreMailer.MoveCssInline(input, removeStyleElements: true, preserveMediaQueries: true);
And your mobile specific style
block should have an ID of ignore
:
<style type="text/css" id="ignore">.target { width: 1337px; }</style>
Premailer specific CSS becomes HTML attributes
Premailer looks for the use of CSS attributes prefixed with -premailer
and will proxy the value through to the DOM element as an attribute.
For example
table {
-premailer-cellspacing: 5;
-premailer-width: 500;
}
will make a table
element render as
<table cellspacing="5" width="500">
Analytics Tags
The AddAnalyticsTags
method can be used to add Google Analytics tracking parameters to links in your HTML:
var pm = new PreMailer(htmlSource);
pm.AddAnalyticsTags(
source: "newsletter", // utm_source parameter
medium: "email", // utm_medium parameter
campaign: "summer_sale", // utm_campaign parameter
content: "logo_link", // utm_content parameter
domain: "example.com" // Optional: only add tags to links matching this domain
);
This will append ?utm_source=newsletter&utm_medium=email&utm_campaign=summer_sale&utm_content=logo_link
to all links, or to links matching the specified domain if provided.
Custom DOM Processing
The Document
property provides access to the underlying IHtmlDocument
object, allowing you to perform custom DOM manipulation before inlining CSS:
using(var pm = new PreMailer(html)){
var document = pm.Document;
// Use AngleSharp to process document before moving css inline...
var result = pm.MoveCssInline();
}
This is useful for advanced scenarios where you need to modify the HTML structure before applying CSS.
Notes
- Pseudo classes/elements which not supported by external dependencies, or doesn't make sense in email, will be ignored and logged to the
InlineResult.Warnings
collection.
Installation
NuGet: PreMailer.Net
Contributors
License
PreMailer.Net is available under the MIT license. See the LICENSE file for more info.
Product | Versions Compatible and additional computed target framework versions. |
---|---|
.NET | net5.0 was computed. net5.0-windows was computed. net6.0 was computed. net6.0-android was computed. net6.0-ios was computed. net6.0-maccatalyst was computed. net6.0-macos was computed. net6.0-tvos was computed. net6.0-windows was computed. net7.0 was computed. net7.0-android was computed. net7.0-ios was computed. net7.0-maccatalyst was computed. net7.0-macos was computed. net7.0-tvos was computed. net7.0-windows was computed. net8.0 was computed. net8.0-android was computed. net8.0-browser was computed. net8.0-ios was computed. net8.0-maccatalyst was computed. net8.0-macos was computed. net8.0-tvos was computed. net8.0-windows was computed. net9.0 was computed. net9.0-android was computed. net9.0-browser was computed. net9.0-ios was computed. net9.0-maccatalyst was computed. net9.0-macos was computed. net9.0-tvos was computed. net9.0-windows was computed. net10.0 was computed. net10.0-android was computed. net10.0-browser was computed. net10.0-ios was computed. net10.0-maccatalyst was computed. net10.0-macos was computed. net10.0-tvos was computed. net10.0-windows was computed. |
.NET Core | netcoreapp2.0 was computed. netcoreapp2.1 was computed. netcoreapp2.2 was computed. netcoreapp3.0 was computed. netcoreapp3.1 was computed. |
.NET Standard | netstandard2.0 is compatible. netstandard2.1 was computed. |
.NET Framework | net461 is compatible. net462 was computed. net463 was computed. net47 was computed. net471 was computed. net472 was computed. net48 was computed. net481 was computed. |
MonoAndroid | monoandroid was computed. |
MonoMac | monomac was computed. |
MonoTouch | monotouch was computed. |
Tizen | tizen40 was computed. tizen60 was computed. |
Xamarin.iOS | xamarinios was computed. |
Xamarin.Mac | xamarinmac was computed. |
Xamarin.TVOS | xamarintvos was computed. |
Xamarin.WatchOS | xamarinwatchos was computed. |
-
.NETFramework 4.6.1
- AngleSharp (>= 1.1.0)
-
.NETStandard 2.0
- AngleSharp (>= 1.1.0)
NuGet packages (29)
Showing the top 5 NuGet packages that depend on PreMailer.Net:
Package | Downloads |
---|---|
Kentico.Xperience.Libraries
The runtime assemblies for libraries and applications that use Kentico Xperience API. |
|
ImmediaC.SimpleCms
ASP.NET Core based CMS |
|
evernote-cloud-sdk-windows
Evernote Cloud SDK for Windows |
|
ActionMailerNext
Package Description |
|
FenixAlliance.ACL.SDK
Application Component for the Alliance Business Suite. |
GitHub repositories (6)
Showing the top 6 popular GitHub repositories that depend on PreMailer.Net:
Repository | Stars |
---|---|
smartstore/SmartStoreNET
Open Source ASP.NET MVC Enterprise eCommerce Shopping Cart Solution
|
|
smartstore/Smartstore
A modular, scalable and ultra-fast open-source all-in-one eCommerce platform built on ASP.NET Core 7
|
|
SparkDevNetwork/Rock
An open source CMS, Relationship Management System (RMS) and Church Management System (ChMS) all rolled into one.
|
|
TerribleDev/OwinOAuthProviders
OAuth providers for Owin
|
|
CervantesSec/cervantes
Cervantes is an open-source, collaborative platform designed specifically for pentesters and red teams. It serves as a comprehensive management tool, streamlining the organization of projects, clients, vulnerabilities, and reports in a single, centralized location.
|
|
DigitalRuby/MailDemon
Smtp server for mass emailing, managing email lists and more. Built on .NET Core. Linux, MAC and Windows compatible.
|
Version | Downloads | Last updated |
---|---|---|
2.7.0 | 3,052 | 6/5/2025 |
2.6.0 | 664,056 | 5/22/2024 |
2.5.0 | 457,953 | 11/24/2023 |
2.4.0 | 3,625,797 | 11/2/2021 |
2.3.0 | 79,482 | 10/8/2021 |
2.2.0 | 3,399,014 | 4/8/2020 |
2.1.3 | 572,489 | 10/30/2019 |
2.1.1 | 74,717 | 9/16/2019 |
2.1.0 | 50,409 | 9/6/2019 |
2.0.1 | 667,610 | 12/7/2018 |
2.0.0 | 993,876 | 7/18/2018 |
2.0.0-beta2 | 97,221 | 3/21/2017 |
2.0.0-beta1 | 2,975 | 3/21/2017 |
1.5.5 | 999,411 | 11/7/2016 |
1.5.4 | 142,666 | 8/2/2016 |
1.5.3 | 83,141 | 4/15/2016 |
1.5.2 | 22,799 | 4/12/2016 |
1.5.1 | 42,932 | 3/29/2016 |
1.5.0 | 26,044 | 2/23/2016 |
1.4.3 | 53,152 | 12/16/2015 |
1.4.2 | 274,599 | 7/29/2015 |
1.4.1 | 45,483 | 5/22/2015 |
1.4.0 | 4,831 | 5/3/2015 |
1.3.1 | 75,851 | 3/22/2015 |
1.3.0 | 70,905 | 3/1/2015 |
1.2.9 | 168,755 | 11/19/2014 |
1.2.8 | 18,453 | 10/28/2014 |
1.2.7 | 292,623 | 7/28/2014 |
1.2.6 | 40,201 | 5/22/2014 |
1.2.5 | 2,551 | 5/22/2014 |
1.2.4 | 120,971 | 2/18/2014 |
1.2.3 | 9,014 | 11/25/2013 |
1.2.2 | 2,815 | 11/13/2013 |
1.2.1 | 2,578 | 11/12/2013 |
1.2.0 | 2,599 | 11/11/2013 |
1.1.3 | 2,982 | 11/7/2013 |
1.1.2 | 17,201 | 6/5/2012 |
1.1.1 | 20,380 | 11/5/2011 |
1.1.0 | 3,926 | 9/29/2011 |
1.0.0 | 6,175 | 9/12/2011 |
What's Changed
* Build(deps): Bump actions/checkout from 4.1.6 to 4.1.7 by @dependabot in https://github.com/milkshakesoftware/PreMailer.Net/pull/409
* Build(deps): Bump actions/setup-dotnet from 4.0.0 to 4.0.1 by @dependabot in https://github.com/milkshakesoftware/PreMailer.Net/pull/411
* Build(deps): Bump pascalgn/automerge-action from 0.16.3 to 0.16.4 by @dependabot in https://github.com/milkshakesoftware/PreMailer.Net/pull/412
* Build(deps): Bump actions/checkout from 4.1.7 to 4.2.0 by @dependabot in https://github.com/milkshakesoftware/PreMailer.Net/pull/413
* Build(deps): Bump actions/checkout from 4.2.0 to 4.2.1 by @dependabot in https://github.com/milkshakesoftware/PreMailer.Net/pull/414
* Build(deps): Bump actions/checkout from 4.2.1 to 4.2.2 by @dependabot in https://github.com/milkshakesoftware/PreMailer.Net/pull/415
* Build(deps): Bump actions/setup-dotnet from 4.0.1 to 4.1.0 by @dependabot in https://github.com/milkshakesoftware/PreMailer.Net/pull/416
* Build(deps): Bump actions/setup-dotnet from 4.1.0 to 4.2.0 by @dependabot in https://github.com/milkshakesoftware/PreMailer.Net/pull/418
* Update target frameworks of test and benchmark projects by @martinnormark in https://github.com/milkshakesoftware/PreMailer.Net/pull/420
* LinkTagCssSource now also downloads content from @import declarations. by @whorchner in https://github.com/milkshakesoftware/PreMailer.Net/pull/419
* Build(deps): Bump actions/setup-dotnet from 4.2.0 to 4.3.0 by @dependabot in https://github.com/milkshakesoftware/PreMailer.Net/pull/421
* Build(deps): Bump actions/setup-dotnet from 4.3.0 to 4.3.1 by @dependabot in https://github.com/milkshakesoftware/PreMailer.Net/pull/423
* Fix #410: Preserve !important tag in inlined styles by @devin-ai-integration in https://github.com/milkshakesoftware/PreMailer.Net/pull/424
* Fix #347: Preserve HTML entities like © during processing by @devin-ai-integration in https://github.com/milkshakesoftware/PreMailer.Net/pull/425
* Update README to accurately document PreMailer API by @devin-ai-integration in https://github.com/milkshakesoftware/PreMailer.Net/pull/426
* Fix #171: Preserve empty HTML tags during serialization by @devin-ai-integration in https://github.com/milkshakesoftware/PreMailer.Net/pull/427
* Fix CSS comment regex to handle protocol-agnostic URLs in premailer attributes by @devin-ai-integration in https://github.com/milkshakesoftware/PreMailer.Net/pull/428
* Fix issue #235: Preserve base64 encoded images and URLs during CSS parsing and style application by @devin-ai-integration in https://github.com/milkshakesoftware/PreMailer.Net/pull/429
Full Changelog: https://github.com/milkshakesoftware/PreMailer.Net/compare/v2.6.0...v2.7.0