MailMergeLib 5.9.1

.NET Standard 2.1 .NET Framework 4.6.2
dotnet add package MailMergeLib --version 5.9.1
NuGet\Install-Package MailMergeLib -Version 5.9.1
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="MailMergeLib" Version="5.9.1" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add MailMergeLib --version 5.9.1
#r "nuget: MailMergeLib, 5.9.1"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install MailMergeLib as a Cake Addin
#addin nuget:?package=MailMergeLib&version=5.9.1

// Install MailMergeLib as a Cake Tool
#tool nuget:?package=MailMergeLib&version=5.9.1


What is MailMergeLib?

MailMergeLib version 5 is an SMTP mail client library which provides comfortable mail merge capabilities. MailMergeLib is written in C# and comes with the following features:

Mail message generation

  • Email templates can be fully individualized in terms of recipients, subject, HTML and/or plain text, attachments and even headers. Placeholders are inserted as variable names from data source between curly braces like so: {MailboxAddress.Name} or with formatting arguments like {Date:yyyy-MM-dd}.
  • HTML text may contain images from local hard disk, which will be automatically inserted as inline attachments.
  • For HTML text MailMergeLib can generate a plain text representation.
  • Attachment sources can be files, streams or strings.
  • The data source for email merge messages to a number of recipients and be any IEnumerable object as well as DataTables. The data source for single emails can be any of the following types: Dictionary<string,object>, ExpandoObject, DataRow, any class instances or anonymous types. For class instances it's even allowed to use the name of parameter less methods.
  • Placeholders in the email can be formatted with any of the features known from string.Format by using SmartFormat.NET. SmartFormat is a parser coming close to string.Format's speed, but bringing a lot of additional options like easy pluralization for many languages.
  • Resulting emails are MimeMessages from MimeKit, an outstanding tool for creating and parsing emails, covering all relevant MIME standards making sure that emails are not qualified as SPAM.
  • Support for international email address format.

Sending email messages

  • Practically unlimited number of parallel tasks to send out individualized emails to a big number of recipients.
  • SmptClients for each task can get their own preconfigured settings, so that e.g. several mail servers can be used for one send job.
  • Progress of processing emails can easily be observed with a number of events.
  • SMTP failures can automatically be resolved supplying a backup configuration. This fault-tolerance is essential for unattended production systems.
  • Emails are sent using the SmtpClient from MailKit, the sister project to MimeKit. SmtpClient is highly flexible and can be configured for literally every scenario you can think of.
  • Instead of sending, emails can also be stored in MIME formatted text files, e.g. if a "pickup directory" from IIS or Microsoft Exchange shall be used. If needed, these files can be loaded back into a MimeMessage from MimeKit.

Save and restore

  • Messages and templates can be saved and loaded to/from XML files.
  • Configuration settings for messages and SMTP can be stored to and loaded from an XML file.


  • Fine grained control over the whole process of email message generation and distribution.
  • Clearly out-performs .NET System.Net.Mail.
  • RFC standards compliant.
  • We aks you not to use MailMergeLib for sending unsolicited bulk email.

Supported Frameworks

  • .Net Framework 4.6.2 and later
  • .Net Standard 2.1 and later


Product Versions
.NET net5.0 net5.0-windows net6.0 net6.0-android net6.0-ios net6.0-maccatalyst net6.0-macos net6.0-tvos net6.0-windows net7.0 net7.0-android net7.0-ios net7.0-maccatalyst net7.0-macos net7.0-tvos net7.0-windows
.NET Core netcoreapp3.0 netcoreapp3.1
.NET Standard netstandard2.1
.NET Framework net462 net463 net47 net471 net472 net48 net481
MonoAndroid monoandroid
MonoMac monomac
MonoTouch monotouch
Tizen tizen60
Xamarin.iOS xamarinios
Xamarin.Mac xamarinmac
Xamarin.TVOS xamarintvos
Xamarin.WatchOS xamarinwatchos
Compatible target framework(s)
Additional computed target framework(s)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last updated
5.9.1 390 1/14/2023
5.8.2 3,955 6/3/2022
5.8.1 312 6/3/2022
5.8.0 661 2/4/2022
5.7.1 29,587 1/5/2021 18,377 11/15/2019
5.6.1 2,040 12/29/2018
5.6.0 1,122 12/28/2018
5.5.0 9,104 6/15/2018
5.4.1 1,517 3/10/2018
5.4.0 1,032 2/17/2018
5.3.0 2,947 8/18/2017 6,769 4/5/2017
5.2.0 1,256 11/12/2016 1,361 10/9/2016

See the change log with links to the Wiki for details of this release: