- Use imap.uid() for search and fetch instead of imap.search/fetch.
Sequence numbers shift when messages are deleted, causing the adapter
to skip new messages or reprocess old ones. UIDs are stable.
- Pass ssl.create_default_context() to starttls() so the server
certificate is actually verified. Without it smtplib uses
ssl._create_stdlib_context() which skips verification.
fa72f4ff55