Top 20 NuGet email Packages

Google Analytics tracking of mail templates, can be set by the editors.
Value object classes and validation for different kinds of global identifiers.
Library written in F# to receive emails. Can be used from C# or F# in end-to-end tests to ensure emails are being sent correctly.
simple email utility
ActionMailerNext is a painless way of using razor view to render emails. This version runs with ASP.MVC 5.3. ActionMailerNext is a continuation of the ActionMailer.Net project.
Adds support for SendGrid SmtpApi and WebHook to emails sent by Composite C1.
zxm.MailKit.Abstractions is zxm.MailKit abstractions.
zxm.MailKit.Outlook365 is an extensions to send email with outlok365.
Provides simple access to Mailgun's REST API from .Net applications: Send messages, create web hooks, manage mailboxes, etc.
Apply Data8 advanced email address and telephone number validation and format standardization for common data types in ASP.NET MVC
Validators for data types that are not available in c# apis
Read and send emails easily.
Examples of semantic classes, including EmailAddress, BirthDate and Amount.
Temptress Templating
A package which encapsulates regular expression patterns for reuse
Helps to plugin emojis in to the Text.
A C# Library for GuerrillaMail api
A library to simplify creating and sending emails with built in support for audiences and templating.
Nequeo mail component
Use Postal to send emails via Amazon SES