Email Scheduler GUI

This is a Python-based GUI application for scheduling and sending emails. It allows you to:

• Configure SMTP settings (server, port, encryption, credentials)
• Schedule emails on a specific time basis (daily, once, weekly, monthly) or on a repeating interval (e.g., every 15 minutes)
• Manually send emails now
• Attach files (e.g., PDFs, images) to your emails
• Store and edit scheduled emails in a local SQLite database

The application uses Tkinter for the GUI and smtplib for sending emails.

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Features

1. SMTP Settings

   • Enter your SMTP server (e.g., smtp.gmail.com or smtp.mailgun.org), port, email address, and password.
   • Choose encryption: SSL, STARTTLS, or NONE.

2. Database-Backed

   • All SMTP settings and emails are stored in a local SQLite database named scheduler.db.
   • Settings persist between runs of the application.

3. Schedules

   • Time-based (Once, Daily, Weekly, or Monthly) at a chosen clock time (HH:MM).
   • Interval-based: send the email every X minutes.

4. Last Sent & Next Send

   • The GUI shows when an email was last sent, as well as an estimate of the next send time.

5. Attachment Support

   • You can attach a single file to an email (e.g., PDF, image, document).
   • Files are MIME-encoded automatically via Python’s EmailMessage.

6. Manual Send

   • Force-send any scheduled email immediately by clicking the Send Now button.

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