Extension support status

[emersion]

List of all extensions: https://www.iana.org/assignments/mail-parameters/mail-parameters.xhtml#mail-parameters-2

Extension	RFC	Client	Server
ESMTP	5321	✓	✓
LMTP	2033	✓	✓
8BITMIME	6152	✓	✓
SIZE	1870	✓	✓
CHUNKING	3030	✗	✓
BINARYMIME	3030	✗	✓
CHECKPOINT	1845	✗	✗
DELIVERBY	2852	✓	✓
PIPELINING	2920	✗	✓
DSN	3461	✓	✓
ETRN	1985	✗	✗
ENHANCEDSTATUSCODES	2034	✓	✓
STARTTLS	3207	✓	✓
NO-SOLICITING	3865	✗	✗
MTRK	3885	✗	✗
ATRN	2645	✗	✗
AUTH	4954	✓	✓
BURL	4468	✗	✗
FUTURERELEASE	4865	✗	✗
CONPERM	4141	✗	✗
CONNEG	4141	✗	✗
SMTPUTF8	6531	✓	✓
MT-PRIORITY	6710	✓	✓
RRVS	7293	✓	✓
REQUIRETLS	8689	✓	✓
LIMITS	9422	✗	✗