Troubleshooting .NET Gmail SMTP Email Sending Issues
Many developers encounter problems sending emails via Gmail's SMTP server using .NET. This guide provides solutions and working code examples.
Common Error: "The SMTP server requires a secure connection or the client was not authenticated."
This error indicates that your Gmail SMTP server requires authentication and a secure connection.
Working Code Example:
This C# code snippet demonstrates successful email sending through Gmail's SMTP server:
using System; using System.Net; using System.Net.Mail; namespace EmailSender { class Program { static void Main(string[] args) { // Configure SMTP client var client = new SmtpClient("smtp.gmail.com", 587) { Credentials = new NetworkCredential("[your_email@gmail.com]", "[your_password]"), EnableSsl = true }; // Create email message var message = new MailMessage { From = new MailAddress("[your_email@gmail.com]"), To = { new MailAddress("[recipient_email@example.com]") }, Subject = "Test Email", Body = "Test email body" }; // Send email try { client.Send(message); Console.WriteLine("Email sent successfully!"); } catch (Exception ex) { Console.WriteLine($"Error sending email: {ex.Message}"); } Console.ReadLine(); } } }
Important Note (2021 and Beyond):
For this code to function correctly, you must enable "less secure apps" access in your Gmail security settings. This setting can be found at http://miracleart.cn/link/380714d486fbd50c0c9dfc7e4d8be9f7. This step is crucial to prevent authentication errors like "5.5.1 Authentication Required". Consider using App Passwords for enhanced security instead of your regular password.
Remember to replace placeholders like [your_email@gmail.com]
, [your_password]
, and [recipient_email@example.com]
with your actual credentials and recipient's email address. If you continue to experience issues, double-check your Gmail settings and ensure that your firewall isn't blocking outgoing SMTP connections.
The above is the detailed content of Why Isn't My .NET Gmail SMTP Email Sending Code Working?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

Polymorphism in C is implemented through virtual functions and abstract classes, enhancing the reusability and flexibility of the code. 1) Virtual functions allow derived classes to override base class methods, 2) Abstract classes define interfaces, and force derived classes to implement certain methods. This mechanism makes the code more flexible and scalable, but attention should be paid to its possible increase in runtime overhead and code complexity.

Yes, function overloading is a polymorphic form in C, specifically compile-time polymorphism. 1. Function overload allows multiple functions with the same name but different parameter lists. 2. The compiler decides which function to call at compile time based on the provided parameters. 3. Unlike runtime polymorphism, function overloading has no extra overhead at runtime, and is simple to implement but less flexible.

The destructor in C is used to free the resources occupied by the object. 1) They are automatically called at the end of the object's life cycle, such as leaving scope or using delete. 2) Resource management, exception security and performance optimization should be considered during design. 3) Avoid throwing exceptions in the destructor and use RAII mode to ensure resource release. 4) Define a virtual destructor in the base class to ensure that the derived class objects are properly destroyed. 5) Performance optimization can be achieved through object pools or smart pointers. 6) Keep the destructor thread safe and concise, and focus on resource release.

C has two main polymorphic types: compile-time polymorphism and run-time polymorphism. 1. Compilation-time polymorphism is implemented through function overloading and templates, providing high efficiency but may lead to code bloating. 2. Runtime polymorphism is implemented through virtual functions and inheritance, providing flexibility but performance overhead.

Implementing polymorphism in C can be achieved through the following steps: 1) use inheritance and virtual functions, 2) define a base class containing virtual functions, 3) rewrite these virtual functions by derived classes, and 4) call these functions using base class pointers or references. Polymorphism allows different types of objects to be treated as objects of the same basis type, thereby improving code flexibility and maintainability.

Yes, polymorphisms in C are very useful. 1) It provides flexibility to allow easy addition of new types; 2) promotes code reuse and reduces duplication; 3) simplifies maintenance, making the code easier to expand and adapt to changes. Despite performance and memory management challenges, its advantages are particularly significant in complex systems.

C destructorscanleadtoseveralcommonerrors.Toavoidthem:1)Preventdoubledeletionbysettingpointerstonullptrorusingsmartpointers.2)Handleexceptionsindestructorsbycatchingandloggingthem.3)Usevirtualdestructorsinbaseclassesforproperpolymorphicdestruction.4

Polymorphisms in C are divided into runtime polymorphisms and compile-time polymorphisms. 1. Runtime polymorphism is implemented through virtual functions, allowing the correct method to be called dynamically at runtime. 2. Compilation-time polymorphism is implemented through function overloading and templates, providing higher performance and flexibility.
