Spam detection is an essential part of modern email systems, and machine learning (ML) plays a crucial role in this area. Here’s a brief overview of how spam detection can be performed using machine learning:

1. Data Collection and Preprocessing:

To build a spam detector, you need a labeled dataset consisting of spam and non-spam (also known as “ham”) emails. Preprocessing involves cleaning the data, tokenizing the text, and removing unnecessary features like stop words, special characters, etc.

1. Feature Extraction:

You can represent the email contents using features like Term Frequency-Inverse Document Frequency (TF-IDF), Bag of Words, or even deep learning embeddings like Word2Vec. The goal is to convert the text into a numerical format that can be fed into a machine learning model.

1. Model Selection:

Various algorithms can be used for spam classification, such as Naive Bayes, Support Vector Machines (SVM), Decision Trees, Random Forests, or deep learning models like Neural Networks. Depending on the data and requirements, you may select an appropriate algorithm.

1. Training the Model:

With the chosen algorithm and processed data, you can now train the model. This involves splitting the data into training and validation sets, tuning hyperparameters, and training the model to predict whether an email is spam or ham.

1. Evaluation:

It’s crucial to evaluate the model’s performance using metrics like accuracy, precision, recall, and F1-score. This helps in understanding how well the model is performing and what improvements can be made.

1. Deployment:

Once satisfied with the model’s performance, you can deploy it within an email system to filter incoming messages. Regular updates and continuous monitoring are essential to adapt to the ever-changing patterns of spam emails.

1. Avoiding Legitimate Emails from Being Classified as Spam:

To ensure that legitimate emails (like bulk emails containing course information) do not get classified as spam, the model must be trained with relevant examples, and certain rules can be established. These rules may include whitelisting specific email addresses, domains, or recognizing specific content patterns. Continual fine-tuning and feedback from users can also help in minimizing false positives.