This is a feature and maintenance release.
- Multiple bug fixes for folding of long header lines, thanks to @caugner
- Add support for RFC2387 child element content-type hint in
multipart/relatedstructures. - Support for Ical event methods other than
REQUEST, thanks to @puhr-mde - Change header folding and param separation to use spaces instead of tabs
- Use ; to separate multiple MIME header params
- Add support for RFC3461 DSN messages
- IMAP example code fixed
- Use PHP temp streams instead of temp files
- Allow for longer SMTP error codes
- Updated Brazilian Portuguese translation
- Throw exceptions on invalid encoding values
- Add Afrikaans translation, thanks to @Donno191
- Updated Farsi/Persian translation
- Add PHP 7.4 to test config
- Remove some ambiguity about setting XMailer property
- Improve error checking in mailing list example
- Drop PHP 5.5 from CI config as it's no longer supported by Travis-CI
- Fix S/MIME signing
- Add constants for encryption type
- More consistent use of constants for encryption, charset, encoding
- Add PHPMailer logo images