Mailer

Overview

VersaTul.Mailer provides SMTP-based email delivery behind a small abstraction layer.

It supports plain text and HTML messages, multiple attachment styles, and token-based templated mail while keeping SMTP configuration separate from dispatch code.

Why Use This Package

Use this package when email delivery is becoming a reusable application capability instead of an isolated SMTP call.

Its main value is separating SMTP settings, dispatch concerns, and attachment handling from the calling workflow.

When To Use This Package

Use this package when you want to:

1. Send SMTP email without binding application code directly to SmtpClient.

2. Send HTML or plain-text messages.

3. Attach files using either Attachment or abstract mail attachment models.

4. Generate outbound mail from a tokenized template.

5. Reuse one dispatcher across notifications, export delivery, and alerting flows.

Installation

Install the package with the .NET CLI:

dotnet add package VersaTul.Mailer

Or with the Package Manager Console:

PM> NuGet\Install-Package VersaTul.Mailer -Version latest

Related Packages

1. Logger Mail for email-backed logging.

2. Collection Streamers for generating attachment content.

3. Configuration Defaults for baseline mailer settings.

Start Here If

1. You need to send operational notifications, reports, or export files through SMTP.

2. You want calling code to avoid direct dependency on SmtpClient.

3. Message templates or attachment payloads are part of the workflow.

Not The Right First Package If

1. You only need local file logging rather than outbound delivery.

2. You are generating export files but do not yet need to send them.

3. Your team needs a full email-template management system rather than an SMTP delivery layer.

Works Well With

1. Collection Streamers when attachments are generated from collections or readers.

2. Logger Mail when operational alerts should be delivered through email.

3. Configuration and Configuration Defaults when mail settings need to stay explicit and reusable.

Core Types And Concepts

IMailDispatcher and MailDispatcher

Main delivery abstraction and implementation.

IMailConfiguration and MailConfiguration

Expose SMTP host, credentials, sender/recipient, attachment size, timeout, and retry settings.

ISmtpClient and SmtpClientWrapper

Wrapper abstraction around SMTP transport.

Key Capabilities

1. Send plain text messages.

2. Send HTML messages.

3. Send messages with Attachment collections.

4. Send messages with abstract IMailAttachment payloads.

5. Send tokenized template messages through SendTemplatedMail().

Basic Example

using VersaTul.Configurations;
using VersaTul.Mailer;
using VersaTul.Mailer.Configurations;
using VersaTul.Mailer.SmtpClients;

var configSettings = new ConfigSettings
{
    { "FromAddress", "alerts@domain.com" },
    { "ToAddress", "ops@domain.com" },
    { "SmtpServer", "127.0.0.1" },
    { "SmtpPort", 25 },
    { "SmtpUserName", "smtp-user" },
    { "SmtpPassword", "smtp-password" },
    { "MaxAttachmentSize", 10000000 }
};

var configuration = new MailConfiguration(configSettings);
var smtpClient = new SmtpClientWrapper(configuration);
var dispatcher = new MailDispatcher(smtpClient);

dispatcher.SendMail(configuration.FromAddress, configuration.ToAddress, "Subject", "Body", isHtml: false);

Template Example

dispatcher.SendTemplatedMail(
    configuration.FromAddress,
    configuration.ToAddress,
    "Welcome",
    "<p>Hello {{FirstName}}, your order {{OrderNumber}} is ready.</p>",
    new Dictionary<string, string>
    {
        ["FirstName"] = "Jane",
        ["OrderNumber"] = "ORD-1001"
    });

Expected Result

When this package is working well:

1. SMTP configuration stays outside the delivery call site,

2. the same dispatcher can send plain text, HTML, and attachment-based messages, and

3. workflows such as reporting, alerts, and notifications can reuse one transport abstraction.

Next Step

1. Read Collection Streamers if the next requirement is generating attachment content.

2. Read Logger Mail if the next requirement is email-backed logging.

3. Read Configuration if you want to centralize the mail settings model more explicitly.

Notes

1. MailConfiguration also exposes SmtpTimeoutMilliseconds, RetryCount, and RetryDelayMilliseconds.

2. The package focuses on delivery, not mail-template storage or rendering engines.

3. This package is the transport layer used by Logger Mail and mail-based export workflows.