I wrote the following code in python. The provided code is a well-structured function called get_emails that retrieves email sender addresses and subjects from a mailbox using IMAP. It handles potential encoding issues in the email headers.

`import re
import imaplib
from email.header import decode_header
import chardet

def get_emails(host, port, username, password):
  """
  Connects to mailbox with specified port, retrieves emails, and prints sender's email address and email subject.

  Args:
      host (str): IMAP server hostname or IP address.
      port (int): Port number for the IMAP connection.
      username (str): Username for mailbox access.
      password (str): Password for mailbox access.
  """
  try:
    if port == 993:
      # Use secure connection (IMAP4_SSL)
      imap = imaplib.IMAP4_SSL(host)
    else:
      # Use non-secure connection (IMAP4)
      imap = imaplib.IMAP4(host, port)
    imap.login(username, password)

    # Select inbox folder (you can change this to a different folder)
    imap.select("INBOX")

    # Search for all emails (you can use more specific search criteria here)
    status, data = imap.search(None, 'ALL')

    # Loop through each email
    for num in data[0].split():
      # Get email details (flags, envelope)
      _, envelope = imap.fetch(num, '(BODY[HEADER])')

      # Extract envelope information
      envelope_info = envelope[0][1]

      # Detect the encoding of the envelope_info
      encoding = chardet.detect(envelope_info)['encoding']

      # Decode the entire envelope_info using the detected encoding
      decoded_info = envelope_info.decode(encoding)

      # Use regular expression to search for specific pattern (replace with your pattern)
      ecre = re.compile(r'your_pattern')  # Modify this for your specific search
      if not ecre.search(decoded_info):
        # Decode the envelope header using appropriate encoding
        decoded_header_info = decode_header(decoded_info)

        # Extract sender and subject from the decoded envelope
        sender = decoded_header_info[6][0] if len(decoded_header_info) > 6 and decoded_header_info[6][0] else ''
        subject = decoded_header_info[1][0] if len(decoded_header_info) > 1 and decoded_header_info[1][0] else ''

        # Isolate the subject string (assuming subject is the second element)
        subject_str = subject if isinstance(subject, str) else ''

        # Detect and decode the subject encoding (if necessary)
        if isinstance(subject_str, bytes):
          subject_encoding = decoded_header_info[1][1] if len(decoded_header_info) > 1 and len(decoded_header_info[1]) > 1 and decoded_header_info[1][1] else 'utf-8'
          subject = subject_str.decode(subject_encoding)

        # Print sender's email address and email subject
        print(f"Sender: {sender}nSubject: {subject}n")

    imap.close()
    imap.logout()
  except imaplib.IMAP4.error as e:
    print(f"Error connecting to mailbox: {e}")`

but the result is not as expected and sometimes are encoded like:

Sender: 
Subject: b'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'

I have tried multiple solutions but get same result.