Simplify IMAP4_TLS class and fix Python 3.14+ compatibility

[seanthegeek]

Fix #618 without needing to access undocumented Python imaplib attributes that should not be modified, such as file. Tested against Gmail IMAP TLS on Python 3.8, 3.13, and 3.14 using this test script

import ssl
from imapclient import IMAPClient


HOST = "imap.gmail.com"
PORT = 993


def main() -> None:
    ctx = ssl.create_default_context()
    with IMAPClient(
        HOST,
        port=PORT,
        ssl=True,
        ssl_context=ctx,
        timeout=30,
    ) as client:
        print("Connected to:", HOST, PORT)
        print("welcome:", client.welcome)

        caps = client.capabilities()
        print("capabilities:", caps)
        print("Successfully connected and ran CAPABILITY without auth.")


if __name__ == "__main__":
    main()

See also

python/cpython#142307
seanthegeek/mailsuite#15
domainaware/parsedmarc#636

[JohnVillalovos]

Would it also make sense to update .github/workflows/main.yml to use Python 3.14?

[seanthegeek]

Would it also make sense to update .github/workflows/main.yml to use Python 3.14?

Good point. Added to workflow and updated docs.